From 6b63727911ee07d88729c6a19f28a63670cb74e7 Mon Sep 17 00:00:00 2001
From: Peter Gerwinski <peter.gerwinski@hs-bochum.de>
Date: Thu, 27 Jun 2024 18:14:23 +0200
Subject: [PATCH] Beispiele und Notizen 27.6.2024
---
20240627/ad-20240627.txt | 70 ++++++++++++++++++++++++++++++
20240627/constructors-01.cpp | 18 ++++++++
20240627/constructors-02.cpp | 24 +++++++++++
20240627/constructors-03.cpp | 30 +++++++++++++
20240627/constructors-04.cpp | 31 ++++++++++++++
20240627/constructors-05.cpp | 37 ++++++++++++++++
20240627/constructors-06.cpp | 38 +++++++++++++++++
20240627/constructors-07.cpp | 44 +++++++++++++++++++
20240627/constructors-08.cpp | 41 ++++++++++++++++++
20240627/constructors-09.cpp | 42 ++++++++++++++++++
20240627/constructors-10.cpp | 42 ++++++++++++++++++
20240627/constructors-11.cpp | 40 +++++++++++++++++
20240627/namespaces-01.cpp | 7 +++
20240627/namespaces-02.cpp | 9 ++++
20240627/namespaces-03.cpp | 9 ++++
20240627/namespaces-04.cpp | 14 ++++++
20240627/namespaces-05.cpp | 14 ++++++
20240627/namespaces-06.cpp | 15 +++++++
20240627/namespaces-07.cpp | 16 +++++++
20240627/namespaces-08.cpp | 15 +++++++
20240627/namespaces-09.cpp | 17 ++++++++
20240627/namespaces-10.cpp | 20 +++++++++
20240627/objects-01.c | 28 ++++++++++++
20240627/objects-02.c | 28 ++++++++++++
20240627/objects-03.c | 34 +++++++++++++++
20240627/objects-04.c | 34 +++++++++++++++
20240627/objects-05.c | 34 +++++++++++++++
20240627/objects-06.c | 39 +++++++++++++++++
20240627/objects-07.c | 43 +++++++++++++++++++
20240627/objects-08.c | 59 +++++++++++++++++++++++++
20240627/objects-09.c | 69 ++++++++++++++++++++++++++++++
20240627/objects-10.c | 76 +++++++++++++++++++++++++++++++++
20240627/objects-11.c | 78 +++++++++++++++++++++++++++++++++
20240627/objects-12.c | 69 ++++++++++++++++++++++++++++++
20240627/objects-13.c | 75 ++++++++++++++++++++++++++++++++
20240627/objects-14.cpp | 55 ++++++++++++++++++++++++
20240627/objects-15.cpp | 57 +++++++++++++++++++++++++
20240627/objects-16.cpp | 55 ++++++++++++++++++++++++
20240627/objects-17.cpp | 55 ++++++++++++++++++++++++
20240627/objects-18.cpp | 60 ++++++++++++++++++++++++++
20240627/objects-19.cpp | 60 ++++++++++++++++++++++++++
20240627/objects-20.cpp | 60 ++++++++++++++++++++++++++
20240627/objects-21.cpp | 72 +++++++++++++++++++++++++++++++
20240627/objects-22.cpp | 74 ++++++++++++++++++++++++++++++++
20240627/objects-23.cpp | 74 ++++++++++++++++++++++++++++++++
20240627/objects-24.cpp | 74 ++++++++++++++++++++++++++++++++
20240627/objects-25.cpp | 79 ++++++++++++++++++++++++++++++++++
20240627/objects-26.cpp | 82 +++++++++++++++++++++++++++++++++++
20240627/objects-27.cpp | 83 ++++++++++++++++++++++++++++++++++++
20240627/strings-01.cpp | 9 ++++
20240627/strings-02.cpp | 11 +++++
20240627/strings-03.cpp | 11 +++++
20240627/strings-04.cpp | 11 +++++
20240627/strings-05.cpp | 9 ++++
20240627/strings-06.cpp | 12 ++++++
20240627/strings-07.cpp | 12 ++++++
56 files changed, 2274 insertions(+)
create mode 100644 20240627/ad-20240627.txt
create mode 100644 20240627/constructors-01.cpp
create mode 100644 20240627/constructors-02.cpp
create mode 100644 20240627/constructors-03.cpp
create mode 100644 20240627/constructors-04.cpp
create mode 100644 20240627/constructors-05.cpp
create mode 100644 20240627/constructors-06.cpp
create mode 100644 20240627/constructors-07.cpp
create mode 100644 20240627/constructors-08.cpp
create mode 100644 20240627/constructors-09.cpp
create mode 100644 20240627/constructors-10.cpp
create mode 100644 20240627/constructors-11.cpp
create mode 100644 20240627/namespaces-01.cpp
create mode 100644 20240627/namespaces-02.cpp
create mode 100644 20240627/namespaces-03.cpp
create mode 100644 20240627/namespaces-04.cpp
create mode 100644 20240627/namespaces-05.cpp
create mode 100644 20240627/namespaces-06.cpp
create mode 100644 20240627/namespaces-07.cpp
create mode 100644 20240627/namespaces-08.cpp
create mode 100644 20240627/namespaces-09.cpp
create mode 100644 20240627/namespaces-10.cpp
create mode 100644 20240627/objects-01.c
create mode 100644 20240627/objects-02.c
create mode 100644 20240627/objects-03.c
create mode 100644 20240627/objects-04.c
create mode 100644 20240627/objects-05.c
create mode 100644 20240627/objects-06.c
create mode 100644 20240627/objects-07.c
create mode 100644 20240627/objects-08.c
create mode 100644 20240627/objects-09.c
create mode 100644 20240627/objects-10.c
create mode 100644 20240627/objects-11.c
create mode 100644 20240627/objects-12.c
create mode 100644 20240627/objects-13.c
create mode 100644 20240627/objects-14.cpp
create mode 100644 20240627/objects-15.cpp
create mode 100644 20240627/objects-16.cpp
create mode 100644 20240627/objects-17.cpp
create mode 100644 20240627/objects-18.cpp
create mode 100644 20240627/objects-19.cpp
create mode 100644 20240627/objects-20.cpp
create mode 100644 20240627/objects-21.cpp
create mode 100644 20240627/objects-22.cpp
create mode 100644 20240627/objects-23.cpp
create mode 100644 20240627/objects-24.cpp
create mode 100644 20240627/objects-25.cpp
create mode 100644 20240627/objects-26.cpp
create mode 100644 20240627/objects-27.cpp
create mode 100644 20240627/strings-01.cpp
create mode 100644 20240627/strings-02.cpp
create mode 100644 20240627/strings-03.cpp
create mode 100644 20240627/strings-04.cpp
create mode 100644 20240627/strings-05.cpp
create mode 100644 20240627/strings-06.cpp
create mode 100644 20240627/strings-07.cpp
diff --git a/20240627/ad-20240627.txt b/20240627/ad-20240627.txt
new file mode 100644
index 0000000..be20d7f
--- /dev/null
+++ b/20240627/ad-20240627.txt
@@ -0,0 +1,70 @@
+Aufgabe: Schreiben Sie die Sinusfunktion selbst.
+~~~~~~~~
+ - Wir setzen nur die Grundrechenarten voraus.
+ - möglichst effizient
+
+Lösungsansätze:
+ - Taylor-Reihe: sin x = x - x^3 / 3! + x^5 / 5! - x^7 / 7! + ...
+ - Kleinwinkelnäherung: Spezialfall der Taylor-Reihe
+ - Verallgemeinerung der Taylor-Reihe: mathematische Folge, die gegen die Lösung konvergiert
+ - Differentialgleichung lösen: f''(x) = -f(x) mit f(0) = 0, f'(0) = 1
+ - möglichst effizient: Tabelle abspeichern, interpolieren
+ - Drehmatrizen --> CORDIC-Algorithmus
+
+
+.----------------------------------------------------------------------------.
+| Bis 17:45 Uhr bitte einen selbstgewählten Lösungsansatz implementieren, |
+| so daß der berechnete Sinus mit dem Sinus der Laufzeitbibliothek möglichst |
+| gut übereinstimmt. Dann vergleichen wir die Ergebnisse in Hinblick auf |
+| Genauigkeit, Verbrauch an Rechenzeit, Verbrauch an Speicherplatz. |
+| (Die verwendete Computersprache ist beliebig. Aber bitte erklären können.) |
+`----------------------------------------------------------------------------'
+
+ pi = 3.1415926535897932384626433...
+ 22/7 = 3.1428...
+355/113 = 3.14159292...
+(siehe auch: https://xkcd.com/2205/)
+
+sin (218 * 3.14159265358979323846 / 180) = -0.61566147532565827966
+ sin (45 * 3.14159265358979323846 / 180) = 0.70710678118654752439
+sin (360 * 3.14159265358979323846 / 180) = 0.00000000000000000000
+ sin (90 * 3.14159265358979323846 / 180) = 1.00000000000000000000
+ sin (30 * 3.14159265358979323846 / 180) = 0.49999999999999999999 = 0.5
+
+Taylor-Reihe bis 10: 5-6 Stellen Genauigkeit
+längere Taylor-Reihe: 15-16 Stellen Genauigkeit
+längere Taylor-Reihe rückwärts: Double-Genauigkeit :-)
+
+
+Achtung: Wenn man stark unterschiedliche Gleitkommazahlen addiert,
+verliert man Rechengenauigkeit!
+
+Beispiel: Rechenwerk mit 5 Dezimalstellen Genauigkeit
+ 1 = 1e0
+ 1000 = 1e3
+ 123.45 = 1.2345e2
+ 123.45 + 0.0123 = 123.46 <-- Wir verlieren 2 Stellen Genauigkeit!
+
+ 123.45 + 123.45 + 123.45 + ... + 123.45 + 123.45 (101 Summanden)
+ `-------------------v-----------------'
+ Summe so groß, daß der letzte Summand nur noch sehr ungenau zum Zuge kommt
+ (vereinfacht: 12345.0 + 123.45 = 12468.0, wir verlieren 2 Stellen)
+
+ --> Beim Aufsummieren erst kleine Zahlen addieren,
+ so daß man insgesamt immer ungefähr gleich große Zahlen addiert
+
+
+Drehmatrizen: (siehe auch: https://xkcd.com/184/)
+
+ . .
+ | cos x -sin x |
+ | | dreht einen Vektor um den Winkel x
+ | sin x cos x |
+ ` '
+
+ ... kann ich hintereinanderschalten.
+
+ Sammlung von Drehmatrizen: Drehung um pi/2, pi/4, pi/8, pi/16, ...
+ --> Winkel x liegt binär vor --> aus abgespeicherten Matrizen schnell eine zusammensetzen,
+ die um den Winkel x dreht
+ --> CORDIC-Algorithmus
diff --git a/20240627/constructors-01.cpp b/20240627/constructors-01.cpp
new file mode 100644
index 0000000..7971c5a
--- /dev/null
+++ b/20240627/constructors-01.cpp
@@ -0,0 +1,18 @@
+#include <stdio.h>
+
+struct Hello
+{
+ void hello ();
+};
+
+void Hello::hello ()
+{
+ printf ("Hello, world!\n");
+}
+
+int main ()
+{
+ Hello h;
+ h.hello ();
+ return 0;
+}
diff --git a/20240627/constructors-02.cpp b/20240627/constructors-02.cpp
new file mode 100644
index 0000000..fba4832
--- /dev/null
+++ b/20240627/constructors-02.cpp
@@ -0,0 +1,24 @@
+#include <stdio.h>
+
+struct Hello
+{
+ void hello ();
+ Hello ();
+};
+
+void Hello::hello ()
+{
+ printf ("Hello, world!\n");
+}
+
+Hello::Hello ()
+{
+ printf ("constructor: Hello::Hello\n");
+}
+
+int main ()
+{
+ Hello h;
+ h.hello ();
+ return 0;
+}
diff --git a/20240627/constructors-03.cpp b/20240627/constructors-03.cpp
new file mode 100644
index 0000000..47d4880
--- /dev/null
+++ b/20240627/constructors-03.cpp
@@ -0,0 +1,30 @@
+#include <stdio.h>
+
+struct Hello
+{
+ void hello ();
+ Hello ();
+ virtual ~Hello ();
+};
+
+void Hello::hello ()
+{
+ printf ("Hello, world!\n");
+}
+
+Hello::Hello ()
+{
+ printf ("constructor: Hello::Hello\n");
+}
+
+Hello::~Hello ()
+{
+ printf ("destructor: Hello::~Hello\n");
+}
+
+int main ()
+{
+ Hello h;
+ h.hello ();
+ return 0;
+}
diff --git a/20240627/constructors-04.cpp b/20240627/constructors-04.cpp
new file mode 100644
index 0000000..8265819
--- /dev/null
+++ b/20240627/constructors-04.cpp
@@ -0,0 +1,31 @@
+#include <stdio.h>
+
+struct Hello
+{
+ void hello ();
+ Hello ();
+ virtual ~Hello ();
+};
+
+void Hello::hello ()
+{
+ printf ("Hello, world!\n");
+}
+
+Hello::Hello ()
+{
+ printf ("constructor: Hello::Hello\n");
+}
+
+Hello::~Hello ()
+{
+ printf ("destructor: Hello::~Hello\n");
+}
+
+int main ()
+{
+ Hello h1;
+ Hello h2 = h1;
+ h2.hello ();
+ return 0;
+}
diff --git a/20240627/constructors-05.cpp b/20240627/constructors-05.cpp
new file mode 100644
index 0000000..592603c
--- /dev/null
+++ b/20240627/constructors-05.cpp
@@ -0,0 +1,37 @@
+#include <stdio.h>
+
+struct Hello
+{
+ void hello ();
+ Hello ();
+ Hello (const Hello &h);
+ virtual ~Hello ();
+};
+
+void Hello::hello ()
+{
+ printf ("Hello, world!\n");
+}
+
+Hello::Hello ()
+{
+ printf ("constructor: Hello::Hello ()\n");
+}
+
+Hello::Hello (const Hello &h)
+{
+ printf ("constructor: Hello::Hello (const Hello &h)\n");
+}
+
+Hello::~Hello ()
+{
+ printf ("destructor: Hello::~Hello ()\n");
+}
+
+int main ()
+{
+ Hello h1;
+ Hello h2 = h1;
+ h2.hello ();
+ return 0;
+}
diff --git a/20240627/constructors-06.cpp b/20240627/constructors-06.cpp
new file mode 100644
index 0000000..27262ce
--- /dev/null
+++ b/20240627/constructors-06.cpp
@@ -0,0 +1,38 @@
+#include <stdio.h>
+
+struct Hello
+{
+ void hello ();
+ Hello ();
+ Hello (const Hello &h);
+ virtual ~Hello ();
+};
+
+void Hello::hello ()
+{
+ printf ("Hello, world!\n");
+}
+
+Hello::Hello ()
+{
+ printf ("constructor: Hello::Hello ()\n");
+}
+
+Hello::Hello (const Hello &h)
+{
+ printf ("constructor: Hello::Hello (const Hello &h)\n");
+}
+
+Hello::~Hello ()
+{
+ printf ("destructor: Hello::~Hello ()\n");
+}
+
+int main ()
+{
+ Hello h1;
+ Hello h2;
+ h2 = h1;
+ h2.hello ();
+ return 0;
+}
diff --git a/20240627/constructors-07.cpp b/20240627/constructors-07.cpp
new file mode 100644
index 0000000..a0451a0
--- /dev/null
+++ b/20240627/constructors-07.cpp
@@ -0,0 +1,44 @@
+#include <stdio.h>
+
+struct Hello
+{
+ void hello ();
+ Hello ();
+ Hello (const Hello &h);
+ virtual ~Hello ();
+ operator = (const Hello &h);
+};
+
+void Hello::hello ()
+{
+ printf ("Hello, world!\n");
+}
+
+Hello::Hello ()
+{
+ printf ("constructor: Hello::Hello ()\n");
+}
+
+Hello::Hello (const Hello &h)
+{
+ printf ("constructor: Hello::Hello (const Hello &h)\n");
+}
+
+operator Hello::= (const Hello &h)
+{
+ printf ("operator: Hello = Hello\n");
+}
+
+Hello::~Hello ()
+{
+ printf ("destructor: Hello::~Hello ()\n");
+}
+
+int main ()
+{
+ Hello h1;
+ Hello h2;
+ h2 = h1;
+ h2.hello ();
+ return 0;
+}
diff --git a/20240627/constructors-08.cpp b/20240627/constructors-08.cpp
new file mode 100644
index 0000000..0b8d0a0
--- /dev/null
+++ b/20240627/constructors-08.cpp
@@ -0,0 +1,41 @@
+#include <stdio.h>
+
+struct Hello
+{
+
+ void hello ()
+ {
+ printf ("Hello, world!\n");
+ }
+
+ Hello ()
+ {
+ printf ("constructor: Hello::Hello ()\n");
+ }
+
+ Hello (const Hello &h)
+ {
+ printf ("constructor: Hello::Hello (const Hello &h)\n");
+ }
+
+ virtual ~Hello ()
+ {
+ printf ("destructor: Hello::~Hello ()\n");
+ }
+
+ Hello &operator = (const Hello &h)
+ {
+ printf ("operator: Hello = Hello\n");
+ return *this;
+ }
+
+};
+
+int main ()
+{
+ Hello h1;
+ Hello h2;
+ h2 = h1;
+ h2.hello ();
+ return 0;
+}
diff --git a/20240627/constructors-09.cpp b/20240627/constructors-09.cpp
new file mode 100644
index 0000000..33ca3f6
--- /dev/null
+++ b/20240627/constructors-09.cpp
@@ -0,0 +1,42 @@
+#include <stdio.h>
+
+struct Hello
+{
+
+ void hello ()
+ {
+ printf ("Hello, world!\n");
+ }
+
+ Hello ()
+ {
+ printf ("constructor: Hello::Hello ()\n");
+ }
+
+ Hello (const Hello &h)
+ {
+ printf ("constructor: Hello::Hello (const Hello &h)\n");
+ }
+
+ virtual ~Hello ()
+ {
+ printf ("destructor: Hello::~Hello ()\n");
+ }
+
+ Hello &operator = (const Hello &h)
+ {
+ printf ("operator: Hello = Hello\n");
+ return *this;
+ }
+
+};
+
+int main ()
+{
+ Hello *h1 = new Hello ();
+ Hello *h2 = new Hello (h1);
+ h2->hello ();
+ delete h1;
+ delete h2;
+ return 0;
+}
diff --git a/20240627/constructors-10.cpp b/20240627/constructors-10.cpp
new file mode 100644
index 0000000..399f7db
--- /dev/null
+++ b/20240627/constructors-10.cpp
@@ -0,0 +1,42 @@
+#include <stdio.h>
+
+struct Hello
+{
+
+ void hello ()
+ {
+ printf ("Hello, world!\n");
+ }
+
+ Hello ()
+ {
+ printf ("constructor: Hello::Hello ()\n");
+ }
+
+ Hello (const Hello &h)
+ {
+ printf ("constructor: Hello::Hello (const Hello &h)\n");
+ }
+
+ virtual ~Hello ()
+ {
+ printf ("destructor: Hello::~Hello ()\n");
+ }
+
+ Hello &operator = (const Hello &h)
+ {
+ printf ("operator: Hello = Hello\n");
+ return *this;
+ }
+
+};
+
+int main ()
+{
+ Hello *h1 = new Hello ();
+ Hello *h2 = new Hello (*h1);
+ h2->hello ();
+ delete h1;
+ delete h2;
+ return 0;
+}
diff --git a/20240627/constructors-11.cpp b/20240627/constructors-11.cpp
new file mode 100644
index 0000000..6275a03
--- /dev/null
+++ b/20240627/constructors-11.cpp
@@ -0,0 +1,40 @@
+#include <stdio.h>
+
+struct Hello
+{
+
+ void hello ()
+ {
+ printf ("Hello, world!\n");
+ }
+
+ Hello ()
+ {
+ printf ("constructor: Hello::Hello ()\n");
+ }
+
+ Hello (const Hello &h)
+ {
+ printf ("constructor: Hello::Hello (const Hello &h)\n");
+ }
+
+ virtual ~Hello ()
+ {
+ printf ("destructor: Hello::~Hello ()\n");
+ }
+
+ Hello &operator = (const Hello &h)
+ {
+ printf ("operator: Hello = Hello\n");
+ return *this;
+ }
+
+};
+
+int main ()
+{
+ Hello *h1 = new Hello ();
+ Hello *h2 = new Hello (*h1);
+ h2->hello ();
+ return 0;
+}
diff --git a/20240627/namespaces-01.cpp b/20240627/namespaces-01.cpp
new file mode 100644
index 0000000..04f85e5
--- /dev/null
+++ b/20240627/namespaces-01.cpp
@@ -0,0 +1,7 @@
+#include <iostream>
+
+int main ()
+{
+ std::cout << "Hello, world!" << std::endl;
+ return 0;
+}
diff --git a/20240627/namespaces-02.cpp b/20240627/namespaces-02.cpp
new file mode 100644
index 0000000..f9a2dd5
--- /dev/null
+++ b/20240627/namespaces-02.cpp
@@ -0,0 +1,9 @@
+#include <iostream>
+
+using namespace std;
+
+int main ()
+{
+ cout << "Hello, world!" << endl;
+ return 0;
+}
diff --git a/20240627/namespaces-03.cpp b/20240627/namespaces-03.cpp
new file mode 100644
index 0000000..ba3d728
--- /dev/null
+++ b/20240627/namespaces-03.cpp
@@ -0,0 +1,9 @@
+#include <iostream>
+
+using std::cout, std::endl;
+
+int main ()
+{
+ cout << "Hello, world!" << endl;
+ return 0;
+}
diff --git a/20240627/namespaces-04.cpp b/20240627/namespaces-04.cpp
new file mode 100644
index 0000000..9509bd3
--- /dev/null
+++ b/20240627/namespaces-04.cpp
@@ -0,0 +1,14 @@
+#include <iostream>
+
+using std::cout, std::endl;
+
+namespace greeting
+{
+ const char *hello = "Hello, world!";
+}
+
+int main ()
+{
+ cout << hello << endl;
+ return 0;
+}
diff --git a/20240627/namespaces-05.cpp b/20240627/namespaces-05.cpp
new file mode 100644
index 0000000..0cb37c8
--- /dev/null
+++ b/20240627/namespaces-05.cpp
@@ -0,0 +1,14 @@
+#include <iostream>
+
+using std::cout, std::endl;
+
+namespace greeting
+{
+ const char *hello = "Hello, world!";
+}
+
+int main ()
+{
+ cout << greeting::hello << endl;
+ return 0;
+}
diff --git a/20240627/namespaces-06.cpp b/20240627/namespaces-06.cpp
new file mode 100644
index 0000000..1d19c82
--- /dev/null
+++ b/20240627/namespaces-06.cpp
@@ -0,0 +1,15 @@
+#include <iostream>
+
+using std::cout, std::endl;
+
+class greeting
+{
+public:
+ const char *hello = "Hello, world!";
+};
+
+int main ()
+{
+ cout << greeting::hello << endl;
+ return 0;
+}
diff --git a/20240627/namespaces-07.cpp b/20240627/namespaces-07.cpp
new file mode 100644
index 0000000..436c80b
--- /dev/null
+++ b/20240627/namespaces-07.cpp
@@ -0,0 +1,16 @@
+#include <iostream>
+
+using std::cout, std::endl;
+
+class greeting
+{
+public:
+ const char *hello = "Hello, world!";
+};
+
+int main ()
+{
+ greeting Hello;
+ cout << Hello.hello << endl;
+ return 0;
+}
diff --git a/20240627/namespaces-08.cpp b/20240627/namespaces-08.cpp
new file mode 100644
index 0000000..4ebeac0
--- /dev/null
+++ b/20240627/namespaces-08.cpp
@@ -0,0 +1,15 @@
+#include <iostream>
+
+using std::cout, std::endl;
+
+class greeting
+{
+public:
+ static const char *hello = "Hello, world!";
+};
+
+int main ()
+{
+ cout << greeting::hello << endl;
+ return 0;
+}
diff --git a/20240627/namespaces-09.cpp b/20240627/namespaces-09.cpp
new file mode 100644
index 0000000..df8c957
--- /dev/null
+++ b/20240627/namespaces-09.cpp
@@ -0,0 +1,17 @@
+#include <iostream>
+
+using std::cout, std::endl;
+
+class greeting
+{
+public:
+ static const char *hello;
+};
+
+const char *greeting::hello = "Hello, world!";
+
+int main ()
+{
+ cout << greeting::hello << endl;
+ return 0;
+}
diff --git a/20240627/namespaces-10.cpp b/20240627/namespaces-10.cpp
new file mode 100644
index 0000000..28ace28
--- /dev/null
+++ b/20240627/namespaces-10.cpp
@@ -0,0 +1,20 @@
+#include <iostream>
+
+using std::cout, std::endl;
+
+class greeting
+{
+public:
+ static void hello ();
+};
+
+void greeting::hello ()
+{
+ cout << "Hello, world!" << endl;
+}
+
+int main ()
+{
+ greeting::hello ();
+ return 0;
+}
diff --git a/20240627/objects-01.c b/20240627/objects-01.c
new file mode 100644
index 0000000..1a62866
--- /dev/null
+++ b/20240627/objects-01.c
@@ -0,0 +1,28 @@
+#include <stdio.h>
+
+typedef struct
+{
+ int type;
+} t_base;
+
+typedef struct
+{
+ int type;
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ char *content;
+} t_string;
+
+int main (void)
+{
+ t_integer i = { 1, 42 };
+ t_string s = { 2, "Hello, world!" };
+
+ t_base *object[] = { &i, &s };
+
+ return 0;
+}
diff --git a/20240627/objects-02.c b/20240627/objects-02.c
new file mode 100644
index 0000000..a47cfb4
--- /dev/null
+++ b/20240627/objects-02.c
@@ -0,0 +1,28 @@
+#include <stdio.h>
+
+typedef struct
+{
+ int type;
+} t_base;
+
+typedef struct
+{
+ int type;
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ char *content;
+} t_string;
+
+int main (void)
+{
+ t_integer i = { 1, 42 };
+ t_string s = { 2, "Hello, world!" };
+
+ t_base *object[] = { (t_base *) &i, (t_base *) &s };
+
+ return 0;
+}
diff --git a/20240627/objects-03.c b/20240627/objects-03.c
new file mode 100644
index 0000000..ff9224c
--- /dev/null
+++ b/20240627/objects-03.c
@@ -0,0 +1,34 @@
+#include <stdio.h>
+
+typedef struct
+{
+ int type;
+} t_base;
+
+typedef struct
+{
+ int type;
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ char *content;
+} t_string;
+
+int main (void)
+{
+ t_integer i = { 1, 42 };
+ t_string s = { 2, "Hello, world!" };
+
+ t_base *object[] = { (t_base *) &i, (t_base *) &s };
+
+ for (int i = 0; i < 2; i++)
+ if (object[i]->type == 1)
+ printf ("Integer: %d\n", object[i]->content);
+ else if (object[i]->type == 2)
+ printf ("String: \"%s\"\n", object[i]->content);
+
+ return 0;
+}
diff --git a/20240627/objects-04.c b/20240627/objects-04.c
new file mode 100644
index 0000000..ef7bffe
--- /dev/null
+++ b/20240627/objects-04.c
@@ -0,0 +1,34 @@
+#include <stdio.h>
+
+typedef struct
+{
+ int type;
+} t_base;
+
+typedef struct
+{
+ int type;
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ char *content;
+} t_string;
+
+int main (void)
+{
+ t_integer i = { 1, 42 };
+ t_string s = { 2, "Hello, world!" };
+
+ t_base *object[] = { (t_base *) &i, (t_base *) &s };
+
+ for (int i = 0; i < 2; i++)
+ if (object[i]->type == 1)
+ printf ("Integer: %d\n", (t_integer *) object[i]->content);
+ else if (object[i]->type == 2)
+ printf ("String: \"%s\"\n", (t_string *) object[i]->content);
+
+ return 0;
+}
diff --git a/20240627/objects-05.c b/20240627/objects-05.c
new file mode 100644
index 0000000..820181d
--- /dev/null
+++ b/20240627/objects-05.c
@@ -0,0 +1,34 @@
+#include <stdio.h>
+
+typedef struct
+{
+ int type;
+} t_base;
+
+typedef struct
+{
+ int type;
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ char *content;
+} t_string;
+
+int main (void)
+{
+ t_integer i = { 1, 42 };
+ t_string s = { 2, "Hello, world!" };
+
+ t_base *object[] = { (t_base *) &i, (t_base *) &s };
+
+ for (int i = 0; i < 2; i++)
+ if (object[i]->type == 1)
+ printf ("Integer: %d\n", ((t_integer *) object[i])->content);
+ else if (object[i]->type == 2)
+ printf ("String: \"%s\"\n", ((t_string *) object[i])->content);
+
+ return 0;
+}
diff --git a/20240627/objects-06.c b/20240627/objects-06.c
new file mode 100644
index 0000000..86847c9
--- /dev/null
+++ b/20240627/objects-06.c
@@ -0,0 +1,39 @@
+#include <stdio.h>
+
+typedef struct
+{
+ int type;
+} t_base;
+
+typedef struct
+{
+ int type;
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ char *content;
+} t_string;
+
+void print_object (t_base *this)
+{
+ if (this->type == 1)
+ printf ("Integer: %d\n", ((t_integer *) this)->content);
+ else if (this->type == 2)
+ printf ("String: \"%s\"\n", ((t_string *) this)->content);
+}
+
+int main (void)
+{
+ t_integer i = { 1, 42 };
+ t_string s = { 2, "Hello, world!" };
+
+ t_base *object[] = { (t_base *) &i, (t_base *) &s };
+
+ for (int i = 0; i < 2; i++)
+ print_object (object[i]);
+
+ return 0;
+}
diff --git a/20240627/objects-07.c b/20240627/objects-07.c
new file mode 100644
index 0000000..b9b24ad
--- /dev/null
+++ b/20240627/objects-07.c
@@ -0,0 +1,43 @@
+#include <stdio.h>
+
+#define T_BASE 0
+#define T_INTEGER 1
+#define T_STRING 2
+
+typedef struct
+{
+ int type;
+} t_base;
+
+typedef struct
+{
+ int type;
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ char *content;
+} t_string;
+
+void print_object (t_base *this)
+{
+ if (this->type == T_INTEGER)
+ printf ("Integer: %d\n", ((t_integer *) this)->content);
+ else if (this->type == T_STRING)
+ printf ("String: \"%s\"\n", ((t_string *) this)->content);
+}
+
+int main (void)
+{
+ t_integer i = { T_INTEGER, 42 };
+ t_string s = { T_STRING, "Hello, world!" };
+
+ t_base *object[] = { (t_base *) &i, (t_base *) &s, NULL };
+
+ for (int i = 0; object[i]; i++)
+ print_object (object[i]);
+
+ return 0;
+}
diff --git a/20240627/objects-08.c b/20240627/objects-08.c
new file mode 100644
index 0000000..0c93e8f
--- /dev/null
+++ b/20240627/objects-08.c
@@ -0,0 +1,59 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define T_BASE 0
+#define T_INTEGER 1
+#define T_STRING 2
+
+typedef struct
+{
+ int type;
+} t_base;
+
+typedef struct
+{
+ int type;
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ char *content;
+} t_string;
+
+void print_object (t_base *this)
+{
+ if (this->type == T_INTEGER)
+ printf ("Integer: %d\n", ((t_integer *) this)->content);
+ else if (this->type == T_STRING)
+ printf ("String: \"%s\"\n", ((t_string *) this)->content);
+}
+
+t_integer *new_integer (int i)
+{
+ t_integer *p = malloc (sizeof (t_integer));
+ p->type = T_INTEGER;
+ p->content = i;
+ return p;
+}
+
+t_string *new_string (char *s)
+{
+ t_string *p = malloc (sizeof (t_string));
+ p->type = T_STRING;
+ p->content = s;
+ return p;
+}
+
+int main (void)
+{
+ t_base *object[] = { (t_base *) new_integer (42),
+ (t_base *) new_string ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ print_object (object[i]);
+
+ return 0;
+}
diff --git a/20240627/objects-09.c b/20240627/objects-09.c
new file mode 100644
index 0000000..3355ce3
--- /dev/null
+++ b/20240627/objects-09.c
@@ -0,0 +1,69 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define T_BASE 0
+#define T_INTEGER 1
+#define T_STRING 2
+
+typedef struct
+{
+ int type;
+} t_base;
+
+typedef struct
+{
+ int type;
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ char *content;
+} t_string;
+
+typedef union
+{
+ t_base base;
+ t_integer integer;
+ t_string string;
+} t_object;
+
+void print_object (t_object *this)
+{
+ if (this->base.type == T_INTEGER)
+ printf ("Integer: %d\n", this->integer.content);
+ else if (this->base.type == T_STRING)
+ printf ("String: \"%s\"\n", this->string.content);
+}
+
+t_object *new_integer (int i)
+{
+ t_object *p = malloc (sizeof (t_integer));
+ p->integer.type = T_INTEGER;
+ p->integer.content = i;
+ return p;
+}
+
+t_object *new_string (char *s)
+{
+ t_object *p = malloc (sizeof (t_string));
+ p->string.type = T_STRING;
+ p->string.content = s;
+ return p;
+}
+
+int main (void)
+{
+ t_object *object[] = { new_integer (42),
+ new_string ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ print_object (object[i]);
+
+ for (int i = 0; object[i]; i++)
+ free (object[i]);
+
+ return 0;
+}
diff --git a/20240627/objects-10.c b/20240627/objects-10.c
new file mode 100644
index 0000000..86787f3
--- /dev/null
+++ b/20240627/objects-10.c
@@ -0,0 +1,76 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define T_BASE 0
+#define T_INTEGER 1
+#define T_STRING 2
+
+typedef struct
+{
+ int type;
+ void (*print) (t_object *this);
+} t_base;
+
+typedef struct
+{
+ int type;
+ void (*print) (t_object *this);
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ void (*print) (t_object *this);
+ char *content;
+} t_string;
+
+typedef union
+{
+ t_base base;
+ t_integer integer;
+ t_string string;
+} t_object;
+
+void print_integer (t_object *this)
+{
+ printf ("Integer: %d\n", this->integer.content);
+}
+
+void print_string (t_object *this)
+{
+ printf ("String: \"%s\"\n", this->string.content);
+}
+
+t_object *new_integer (int i)
+{
+ t_object *p = malloc (sizeof (t_integer));
+ p->integer.type = T_INTEGER;
+ p->integer.print = print_integer;
+ p->integer.content = i;
+ return p;
+}
+
+t_object *new_string (char *s)
+{
+ t_object *p = malloc (sizeof (t_string));
+ p->string.type = T_STRING;
+ p->string.print = print_string;
+ p->string.content = s;
+ return p;
+}
+
+int main (void)
+{
+ t_object *object[] = { new_integer (42),
+ new_string ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->base.print (object[i]);
+
+ for (int i = 0; object[i]; i++)
+ free (object[i]);
+
+ return 0;
+}
diff --git a/20240627/objects-11.c b/20240627/objects-11.c
new file mode 100644
index 0000000..0a921d8
--- /dev/null
+++ b/20240627/objects-11.c
@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define T_BASE 0
+#define T_INTEGER 1
+#define T_STRING 2
+
+union t_object;
+
+typedef struct
+{
+ int type;
+ void (*print) (union t_object *this);
+} t_base;
+
+typedef struct
+{
+ int type;
+ void (*print) (union t_object *this);
+ int content;
+} t_integer;
+
+typedef struct
+{
+ int type;
+ void (*print) (union t_object *this);
+ char *content;
+} t_string;
+
+typedef union t_object
+{
+ t_base base;
+ t_integer integer;
+ t_string string;
+} t_object;
+
+void print_integer (t_object *this)
+{
+ printf ("Integer: %d\n", this->integer.content);
+}
+
+void print_string (t_object *this)
+{
+ printf ("String: \"%s\"\n", this->string.content);
+}
+
+t_object *new_integer (int i)
+{
+ t_object *p = malloc (sizeof (t_integer));
+ p->integer.type = T_INTEGER;
+ p->integer.print = print_integer;
+ p->integer.content = i;
+ return p;
+}
+
+t_object *new_string (char *s)
+{
+ t_object *p = malloc (sizeof (t_string));
+ p->string.type = T_STRING;
+ p->string.print = print_string;
+ p->string.content = s;
+ return p;
+}
+
+int main (void)
+{
+ t_object *object[] = { new_integer (42),
+ new_string ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->base.print (object[i]);
+
+ for (int i = 0; object[i]; i++)
+ free (object[i]);
+
+ return 0;
+}
diff --git a/20240627/objects-12.c b/20240627/objects-12.c
new file mode 100644
index 0000000..3b0dddd
--- /dev/null
+++ b/20240627/objects-12.c
@@ -0,0 +1,69 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+union t_object;
+
+typedef struct
+{
+ void (* print) (union t_object *this);
+} t_base;
+
+typedef struct
+{
+ void (* print) (union t_object *this);
+ int content;
+} t_integer;
+
+typedef struct
+{
+ void (* print) (union t_object *this);
+ char *content;
+} t_string;
+
+typedef union t_object
+{
+ t_base base;
+ t_integer integer;
+ t_string string;
+} t_object;
+
+void print_integer (t_object *this)
+{
+ printf ("Integer: %d\n", this->integer.content);
+}
+
+void print_string (t_object *this)
+{
+ printf ("String: \"%s\"\n", this->string.content);
+}
+
+t_object *new_integer (int i)
+{
+ t_object *p = malloc (sizeof (t_integer));
+ p->integer.print = print_integer;
+ p->integer.content = i;
+ return p;
+}
+
+t_object *new_string (char *s)
+{
+ t_object *p = malloc (sizeof (t_string));
+ p->string.print = print_string;
+ p->string.content = s;
+ return p;
+}
+
+int main (void)
+{
+ t_object *object[] = { new_integer (42),
+ new_string ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->base.print (object[i]);
+
+ for (int i = 0; object[i]; i++)
+ free (object[i]);
+
+ return 0;
+}
diff --git a/20240627/objects-13.c b/20240627/objects-13.c
new file mode 100644
index 0000000..81ef279
--- /dev/null
+++ b/20240627/objects-13.c
@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+union t_object;
+struct t_vmt;
+
+typedef struct
+{
+ struct t_vmt *vmt;
+} t_base;
+
+typedef struct
+{
+ struct t_vmt *vmt;
+ int content;
+} t_integer;
+
+typedef struct
+{
+ struct t_vmt *vmt;
+ char *content;
+} t_string;
+
+typedef union t_object
+{
+ t_base base;
+ t_integer integer;
+ t_string string;
+} t_object;
+
+typedef struct t_vmt
+{
+ void (* print) (union t_object *this);
+} t_vmt;
+
+void print_integer (t_object *this)
+{
+ printf ("Integer: %d\n", this->integer.content);
+}
+
+void print_string (t_object *this)
+{
+ printf ("String: \"%s\"\n", this->string.content);
+}
+
+t_vmt vmt_integer = { print_integer };
+t_vmt vmt_string = { print_string };
+
+t_object *new_integer (int i)
+{
+ t_object *p = malloc (sizeof (t_integer));
+ p->integer.vmt = &vmt_integer;
+ p->integer.content = i;
+ return p;
+}
+
+t_object *new_string (char *s)
+{
+ t_object *p = malloc (sizeof (t_string));
+ p->integer.vmt = &vmt_string;
+ p->string.content = s;
+ return p;
+}
+
+int main (void)
+{
+ t_object *object[] = { new_integer (42),
+ new_string ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->base.vmt->print (object[i]);
+
+ return 0;
+}
diff --git a/20240627/objects-14.cpp b/20240627/objects-14.cpp
new file mode 100644
index 0000000..9032934
--- /dev/null
+++ b/20240627/objects-14.cpp
@@ -0,0 +1,55 @@
+#include <stdio.h>
+
+struct TBase
+{
+ virtual void print () = 0;
+};
+
+struct TInteger: TBase
+{
+ int content;
+ virtual void print ();
+ TInteger (int i);
+};
+
+struct TString: TBase
+{
+ char *content;
+ virtual void print ();
+ TString (char *s);
+};
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (char *s)
+{
+ content = s;
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-15.cpp b/20240627/objects-15.cpp
new file mode 100644
index 0000000..ab8809f
--- /dev/null
+++ b/20240627/objects-15.cpp
@@ -0,0 +1,57 @@
+#include <stdio.h>
+
+struct TBase
+{
+ virtual void print () = 0;
+};
+
+struct TInteger: TBase
+{
+ int content;
+ virtual void print ();
+ TInteger (int i);
+};
+
+struct TString: TBase
+{
+ char *content;
+ virtual void print ();
+ TString (char *s);
+};
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (char *s)
+{
+ content = s;
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ((char *) "Hello, world!"),
+ // objects-15.cpp:45:36: warning: ISO C++ forbids converting
+ // a string constant to ‘char*’ [-Wwrite-strings]
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-16.cpp b/20240627/objects-16.cpp
new file mode 100644
index 0000000..d836ad1
--- /dev/null
+++ b/20240627/objects-16.cpp
@@ -0,0 +1,55 @@
+#include <stdio.h>
+
+struct TBase
+{
+ virtual void print () = 0;
+};
+
+struct TInteger: TBase
+{
+ int content;
+ virtual void print ();
+ TInteger (int i);
+};
+
+struct TString: TBase
+{
+ char *content;
+ virtual void print ();
+ TString (char *s);
+};
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = s;
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-17.cpp b/20240627/objects-17.cpp
new file mode 100644
index 0000000..879b881
--- /dev/null
+++ b/20240627/objects-17.cpp
@@ -0,0 +1,55 @@
+#include <stdio.h>
+
+struct TBase
+{
+ virtual void print () = 0;
+};
+
+struct TInteger: TBase
+{
+ int content;
+ virtual void print ();
+ TInteger (int i);
+};
+
+struct TString: TBase
+{
+ const char *content;
+ virtual void print ();
+ TString (const char *s);
+};
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = s;
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-18.cpp b/20240627/objects-18.cpp
new file mode 100644
index 0000000..22ae5ce
--- /dev/null
+++ b/20240627/objects-18.cpp
@@ -0,0 +1,60 @@
+#include <stdio.h>
+
+struct TBase
+{
+ virtual void print ();
+};
+
+struct TInteger: TBase
+{
+ int content;
+ virtual void print ();
+ TInteger (int i);
+};
+
+struct TString: TBase
+{
+ const char *content;
+ virtual void print ();
+ TString (const char *s);
+};
+
+void TBase::print ()
+{
+ print ("Base\n");
+}
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = s;
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-19.cpp b/20240627/objects-19.cpp
new file mode 100644
index 0000000..72fdeae
--- /dev/null
+++ b/20240627/objects-19.cpp
@@ -0,0 +1,60 @@
+#include <stdio.h>
+
+struct TBase
+{
+ virtual void print ();
+};
+
+struct TInteger: TBase
+{
+ int content;
+ virtual void print ();
+ TInteger (int i);
+};
+
+struct TString: TBase
+{
+ const char *content;
+ virtual void print ();
+ TString (const char *s);
+};
+
+void TBase::print ()
+{
+ printf ("Base\n");
+}
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = s;
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-20.cpp b/20240627/objects-20.cpp
new file mode 100644
index 0000000..02d9036
--- /dev/null
+++ b/20240627/objects-20.cpp
@@ -0,0 +1,60 @@
+#include <stdio.h>
+
+struct TBase
+{
+ void print ();
+};
+
+struct TInteger: TBase
+{
+ int content;
+ void print ();
+ TInteger (int i);
+};
+
+struct TString: TBase
+{
+ const char *content;
+ void print ();
+ TString (const char *s);
+};
+
+void TBase::print ()
+{
+ printf ("Base\n");
+}
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = s;
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-21.cpp b/20240627/objects-21.cpp
new file mode 100644
index 0000000..02702e4
--- /dev/null
+++ b/20240627/objects-21.cpp
@@ -0,0 +1,72 @@
+#include <stdio.h>
+
+struct TBase
+{
+ virtual void print ();
+ virtual ~Base ();
+};
+
+struct TInteger: TBase
+{
+ int content;
+ virtual void print ();
+ TInteger (int i);
+};
+
+struct TString: TBase
+{
+ char *content;
+ virtual void print ();
+ TString (const char *s);
+ virtual ~TString ();
+};
+
+void TBase::print ()
+{
+ printf ("Base\n");
+}
+
+TBase::~TBase ()
+{
+}
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = malloc (strlen (s) + 1);
+ strcpy (content, s);
+}
+
+TString::~TString ()
+{
+ free (content);
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-22.cpp b/20240627/objects-22.cpp
new file mode 100644
index 0000000..3a14624
--- /dev/null
+++ b/20240627/objects-22.cpp
@@ -0,0 +1,74 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct TBase
+{
+ virtual void print ();
+ virtual ~TBase ();
+};
+
+struct TInteger: TBase
+{
+ int content;
+ virtual void print ();
+ TInteger (int i);
+};
+
+struct TString: TBase
+{
+ char *content;
+ virtual void print ();
+ TString (const char *s);
+ virtual ~TString ();
+};
+
+void TBase::print ()
+{
+ printf ("Base\n");
+}
+
+TBase::~TBase ()
+{
+}
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = malloc (strlen (s) + 1);
+ strcpy (content, s);
+}
+
+TString::~TString ()
+{
+ free (content);
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-23.cpp b/20240627/objects-23.cpp
new file mode 100644
index 0000000..8c83388
--- /dev/null
+++ b/20240627/objects-23.cpp
@@ -0,0 +1,74 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct TBase
+{
+ virtual void print ();
+ virtual ~TBase ();
+};
+
+struct TInteger: TBase
+{
+ int content;
+ virtual void print ();
+ TInteger (int i);
+};
+
+struct TString: TBase
+{
+ char *content;
+ virtual void print ();
+ TString (const char *s);
+ virtual ~TString ();
+};
+
+void TBase::print ()
+{
+ printf ("Base\n");
+}
+
+TBase::~TBase ()
+{
+}
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = (char *) malloc (strlen (s) + 1);
+ strcpy (content, s);
+}
+
+TString::~TString ()
+{
+ free (content);
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-24.cpp b/20240627/objects-24.cpp
new file mode 100644
index 0000000..413ecd2
--- /dev/null
+++ b/20240627/objects-24.cpp
@@ -0,0 +1,74 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+class TBase
+{
+ virtual void print ();
+ virtual ~TBase ();
+};
+
+class TInteger: TBase
+{
+ int content;
+ virtual void print ();
+ TInteger (int i);
+};
+
+class TString: TBase
+{
+ char *content;
+ virtual void print ();
+ TString (const char *s);
+ virtual ~TString ();
+};
+
+void TBase::print ()
+{
+ printf ("Base\n");
+}
+
+TBase::~TBase ()
+{
+}
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = (char *) malloc (strlen (s) + 1);
+ strcpy (content, s);
+}
+
+TString::~TString ()
+{
+ free (content);
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-25.cpp b/20240627/objects-25.cpp
new file mode 100644
index 0000000..d7a78fa
--- /dev/null
+++ b/20240627/objects-25.cpp
@@ -0,0 +1,79 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+class TBase
+{
+public:
+ virtual void print ();
+ virtual ~TBase ();
+};
+
+class TInteger: public TBase
+{
+private:
+ int content;
+public:
+ virtual void print ();
+ TInteger (int i);
+};
+
+class TString: public TBase
+{
+private:
+ char *content;
+public:
+ virtual void print ();
+ TString (const char *s);
+ virtual ~TString ();
+};
+
+void TBase::print ()
+{
+ printf ("Base\n");
+}
+
+TBase::~TBase ()
+{
+}
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = (char *) malloc (strlen (s) + 1);
+ strcpy (content, s);
+}
+
+TString::~TString ()
+{
+ free (content);
+}
+
+int main (void)
+{
+ TBase *object[] = { new TInteger (42),
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-26.cpp b/20240627/objects-26.cpp
new file mode 100644
index 0000000..9555178
--- /dev/null
+++ b/20240627/objects-26.cpp
@@ -0,0 +1,82 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+class TBase
+{
+public:
+ virtual void print ();
+ virtual ~TBase ();
+};
+
+class TInteger: public TBase
+{
+private:
+ int content;
+public:
+ virtual void print ();
+ TInteger (int i);
+};
+
+class TString: public TBase
+{
+private:
+ char *content;
+public:
+ virtual void print ();
+ TString (const char *s);
+ virtual ~TString ();
+};
+
+void TBase::print ()
+{
+ printf ("Base\n");
+}
+
+TBase::~TBase ()
+{
+}
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = (char *) malloc (strlen (s) + 1);
+ strcpy (content, s);
+}
+
+TString::~TString ()
+{
+ free (content);
+}
+
+int main (void)
+{
+ TInteger *answer = new TInteger (42);
+ TBase *object[] = { answer,
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ printf ("The answer is: %d.\n", answer->content);
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/objects-27.cpp b/20240627/objects-27.cpp
new file mode 100644
index 0000000..091f298
--- /dev/null
+++ b/20240627/objects-27.cpp
@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+class TBase
+{
+public:
+ virtual void print ();
+ virtual ~TBase ();
+};
+
+class TInteger: public TBase
+{
+private:
+ int content;
+public:
+ virtual void print ();
+ TInteger (int i);
+ friend int main ();
+};
+
+class TString: public TBase
+{
+private:
+ char *content;
+public:
+ virtual void print ();
+ TString (const char *s);
+ virtual ~TString ();
+};
+
+void TBase::print ()
+{
+ printf ("Base\n");
+}
+
+TBase::~TBase ()
+{
+}
+
+void TInteger::print ()
+{
+ printf ("Integer: %d\n", content);
+}
+
+void TString::print ()
+{
+ printf ("String: \"%s\"\n", content);
+}
+
+TInteger::TInteger (int i)
+{
+ content = i;
+}
+
+TString::TString (const char *s)
+{
+ content = (char *) malloc (strlen (s) + 1);
+ strcpy (content, s);
+}
+
+TString::~TString ()
+{
+ free (content);
+}
+
+int main (void)
+{
+ TInteger *answer = new TInteger (42);
+ TBase *object[] = { answer,
+ new TString ("Hello, world!"),
+ NULL };
+
+ for (int i = 0; object[i]; i++)
+ object[i]->print ();
+
+ printf ("The answer is: %d.\n", answer->content);
+
+ for (int i = 0; object[i]; i++)
+ delete object[i];
+
+ return 0;
+}
diff --git a/20240627/strings-01.cpp b/20240627/strings-01.cpp
new file mode 100644
index 0000000..c2c9822
--- /dev/null
+++ b/20240627/strings-01.cpp
@@ -0,0 +1,9 @@
+#include <iostream>
+#include <string>
+
+int main ()
+{
+ string hello = "Hello, world!";
+ cout << hello << endl;
+ return 0;
+}
diff --git a/20240627/strings-02.cpp b/20240627/strings-02.cpp
new file mode 100644
index 0000000..380cba3
--- /dev/null
+++ b/20240627/strings-02.cpp
@@ -0,0 +1,11 @@
+#include <iostream>
+#include <string>
+
+using std::string, std::cout, std::endl;
+
+int main ()
+{
+ string hello = "Hello, world!";
+ cout << hello << endl;
+ return 0;
+}
diff --git a/20240627/strings-03.cpp b/20240627/strings-03.cpp
new file mode 100644
index 0000000..aeae49b
--- /dev/null
+++ b/20240627/strings-03.cpp
@@ -0,0 +1,11 @@
+#include <stdio.h>
+#include <string>
+
+using std::string;
+
+int main ()
+{
+ string hello = "Hello, world!";
+ printf ("%s\n", hello);
+ return 0;
+}
diff --git a/20240627/strings-04.cpp b/20240627/strings-04.cpp
new file mode 100644
index 0000000..2ebb315
--- /dev/null
+++ b/20240627/strings-04.cpp
@@ -0,0 +1,11 @@
+#include <stdio.h>
+#include <string>
+
+using std::string;
+
+int main ()
+{
+ string hello = "Hello, world!";
+ printf ("%s\n", hello.c_str ());
+ return 0;
+}
diff --git a/20240627/strings-05.cpp b/20240627/strings-05.cpp
new file mode 100644
index 0000000..163ab7b
--- /dev/null
+++ b/20240627/strings-05.cpp
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main ()
+{
+ char answer[100];
+ snprintf (answer, 100, "The answer is %d.", 42);
+ printf ("%s\n", answer);
+ return 0;
+}
diff --git a/20240627/strings-06.cpp b/20240627/strings-06.cpp
new file mode 100644
index 0000000..efc3c3c
--- /dev/null
+++ b/20240627/strings-06.cpp
@@ -0,0 +1,12 @@
+#include <sstream>
+#include <iostream>
+
+using std::ostringstream, std::cout, std::endl;
+
+int main ()
+{
+ ostringstream answer;
+ answer << "The answer is " << 42 << ".";
+ cout << answer << endl;
+ return 0;
+}
diff --git a/20240627/strings-07.cpp b/20240627/strings-07.cpp
new file mode 100644
index 0000000..5bd0023
--- /dev/null
+++ b/20240627/strings-07.cpp
@@ -0,0 +1,12 @@
+#include <sstream>
+#include <iostream>
+
+using std::ostringstream, std::cout, std::endl;
+
+int main ()
+{
+ ostringstream answer;
+ answer << "The answer is " << 42 << ".";
+ cout << answer.str () << endl;
+ return 0;
+}
--
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