How to construct Java in inheritance

How to construct in inheritance

1. The constructor of the subclass must be called during the construction of its base class.

2. Subclasses can use Super (argument_list) to call the constructor of the base class in their own construction method.

2.1. Use this (argument_list) to call the other construction methods of this class.

2.2. If you call super, you must write the first line of the subclass construction method.

3, if the constructor of the subclass is not shown in the constructor method of the call base class, the system defaults to calling the base class's parameterless construction method.

4, if the subclass constructor method does not display the call base class construction method, and the base class does not have parameterless construction method, then the compilation error.

classsuperclass{Private intN; //Superclass () {//System.out.println ("superclass ()"); //}Superclass (intN) {System.out.println ("Superclass (int n)");  This. N =N; }}classSubclassextendssuperclass{Private intN; Subclass () {Super(300); System.out.println ("Superclass"); } Subclass (intN) {System.out.println ("Subclass (int N):" +N);  This. N =N; }} Public classtestsupersub{ Public Static voidMain (String args[]) {//Subclass SC = new subclass ();Subclass SC2 =NewSubclass (200); }}

Verify the above syntax in turn.

How to construct Java in inheritance