class dojo parent code

1, this 1. to use this, you must be in a situation like this. Otherwise, it will report an error: Fatal error: Using $ this when not in object context.2. this can call methods and attributes in this class, or call methods and attributes that can be called in the parent class. Ii. self 1. self can access static attributes and static methods in this

. private int age;4. Public Test () {5. Name= "Tom";6. age=20;7.}8. public static void Main (string[] args) {9. Test T = new Test ();System.out.println (T.name + "age is" + t.age);11.}12.}Class Parent {private int num = 1;. Public Parent () {System.out.println ("Now initializes the parent

One, this 1, to use this, you will have a situation of the image, otherwise it will error, Fatal error:using $this when the not in object context.2,this can call methods and properties in this class, or can call the adjustable methods and properties in the parent class Two, self 1,self can access static properties and static methods in this

"Error:implicit Super constructor Pet () is undefined. Must explicitly invoke another constructor "　Remember one point: when you construct a subclass, you are bound to call the constructor of the parent class. Because the elements in the parent class also need to be initialized.So the

Extends_function () {Parent::sta_functio N (); Self::p ro_function (); echo "You request Extends_private function"; }} Error_reporting (e_all); $test = new Test1 (); $test->tank (); Subclasses and parent classes have properties and methods of the same name, and methods in subclasses are called when subclasses are instantiated. Test1::test1_function (); Test1::extends_function (); After performi

() { OneSystem.out.println ("Animal is eating."); A } - } - the classHorseextendsanimal{ - Public voideat () { -System.out.println ("Horse is eating."); - } +}This code can be compiled. It appears to violate the sixth rule, but it's actually a bit of a coincidence. The Eat () method of the animal class cannot be inherited, so the Eat () method in the horse

When you read the QT code, you often encounter such a code:Qplayer::qplayer (Qwidget *parent): Qmainwindow (parent)Qplayer is a class, "::" followed by a constructor. But how does the Qmainwindow (parent) after the constructor ":" Be understood?We all know that in C + +, if

. Generally, the order of accessibility is (because C ++ does not have the concept of a package, packet access control is not considered for the moment, which does not affect the discussion here ): public > protected > private Take Java as an example: class Base { protected void sayHello() { System.out.println("Hello in Base"); }}class Child extends Base { public void sayHello() { System.out.println("Hell