Os:windows7 x64
Jdk:jdk-8u131-windows-x64
Ide:eclipse Oxygen Release (4.7.0)
Code:
/** by default, the constructor of a subclass calls the parameterless constructor of the parent class first, but the problem is, what if the parent class does not have a parameterless constructor? * The constructor of the parent class is explicitly specified by Super *///the parent class Father {//Parameter constructor, intpublic Father (int num) {System.out.println ("parent class has a parameter constructor, int");} A parameter constructor, Stringpublic Father (String str) {SYSTEM.OUT.PRINTLN ("parent class has a parameter constructor, string");}} Class Son extends Father {//Subclass no parameter constructor public son () {super (1); System.out.println ("sub-class parameterless constructor");} Subclass has a parameter constructor public Son (int num) {super ("Hello"); System.out.println ("Sub-class has a parameter constructor");}} Class Demo {public static void main (string[] args) {son S1 = new Son (); System.out.println (); Son s2 = new Son (1); }}
Results:
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Write Super statement in JavaSE8 Base subclass constructor to explicitly specify the constructor of the parent class