CDE

Task/Classes/C++/classes-1.cpp

@@ -0,0 +1,29 @@
+class MyClass
+{
+public:
+  void someMethod(); // member function = method
+  MyClass(); // constructor
+private:
+  int variable; // member variable = instance variable
+};
+
+// implementation of constructor
+MyClass::MyClass():
+  variable(0)
+{
+  // here could be more code
+}
+
+// implementation of member function
+void MyClass::someMethod()
+{
+  variable = 1; // alternatively: this->variable = 1
+}
+
+// Create an instance as variable
+MyClass instance;
+
+// Create an instance on free store
+MyClass* pInstance = new MyClass;
+// Instances allocated with new must be explicitly destroyed when not needed any more:
+delete pInstance;

Task/Classes/C++/classes-2.cpp

@@ -0,0 +1,8 @@
+class MyClass
+{
+public:
+  MyClass(): variable(0) {}
+  void someMethod() { variable = 1; }
+private:
+  int variable;
+};

Task/Classes/C++/classes-3.cpp

@@ -0,0 +1,6 @@
+class MyClass
+{
+public:
+  virtual void someMethod(); // this is polymorphic
+  virtual ~MyClass(); // destructor
+};

Task/Classes/Common-Lisp/classes.lisp

@@ -0,0 +1,12 @@
+(defclass circle ()
+  ((radius :initarg :radius
+           :initform 1.0
+           :type number
+           :reader radius)))
+
+(defmethod area ((shape circle))
+  (* pi (expt (radius shape) 2)))
+
+> (defvar *c* (make-instance 'circle :radius 2))
+> (area *c*)
+12.566370614359172d0

Task/Classes/D/classes.d

@@ -0,0 +1,43 @@
+import std.stdio;
+
+class MyClass {
+    //constructor (not necessary if empty)
+    this() {}
+
+    void someMethod() {
+        variable = 1;
+    }
+
+    // getter method
+    @property int variable() const {
+        return variable_;
+    }
+
+    // setter method
+    @property int variable(int newVariable) {
+        return variable_ = newVariable;
+    }
+
+    private int variable_;
+}
+
+void main() {
+    // On default class instances are allocated on the heap
+    // The GC will manage their lifetime
+    auto obj = new MyClass();
+
+    // prints 'variable = 0', ints are initialized to 0 by default
+    writeln("variable = ", obj.variable);
+
+    // invoke the method
+    obj.someMethod();
+
+    // prints 'variable = 1'
+    writeln("variable = ", obj.variable);
+
+    // set the variable using setter method
+    obj.variable = 99;
+
+    // prints 'variable = 99'
+    writeln("variable = ", obj.variable);
+}

Task/Classes/DWScript/classes.dwscript

@@ -0,0 +1,25 @@
+type
+  TMyClass = class
+  private
+    FSomeField: Integer; // by convention, fields are usually private and exposed as properties
+  public
+    constructor Create;
+    begin
+       FSomeField := -1;
+    end;
+    procedure SomeMethod;
+    property SomeField: Integer read FSomeField write FSomeField;
+  end;
+
+procedure TMyClass.SomeMethod;
+begin
+  // do something
+end;
+
+
+var lMyClass: TMyClass;
+
+lMyClass := new TMyClass; // can also use TMyClass.Create
+
+lMyClass.SomeField := 99;
+lMyClass.SomeMethod;

Task/Classes/Delphi/classes.delphi

@@ -0,0 +1,44 @@
+program SampleClass;
+
+{$APPTYPE CONSOLE}
+
+type
+  TMyClass = class
+  private
+    FSomeField: Integer; // by convention, fields are usually private and exposed as properties
+  public
+    constructor Create;
+    destructor Destroy; override;
+    procedure SomeMethod;
+    property SomeField: Integer read FSomeField write FSomeField;
+  end;
+
+constructor TMyClass.Create;
+begin
+  FSomeField := -1
+end;
+
+destructor TMyClass.Destroy;
+begin
+  // free resources, etc
+
+  inherited Destroy;
+end;
+
+procedure TMyClass.SomeMethod;
+begin
+  // do something
+end;
+
+
+var
+  lMyClass: TMyClass;
+begin
+  lMyClass := TMyClass.Create;
+  try
+    lMyClass.SomeField := 99;
+    lMyClass.SomeMethod();
+  finally
+    lMyClass.Free;
+  end;
+end.

Task/Classes/E/classes-1.e

@@ -0,0 +1,8 @@
+def makeColor(name :String) {
+    def color {
+        to colorize(thing :String) {
+          return `$name $thing`
+        }
+    }
+    return color
+}

Task/Classes/E/classes-2.e

@@ -0,0 +1,5 @@
+? def red := makeColor("red")
+# value: <color>
+
+? red.colorize("apple")
+# value: "red apple"