自学java第30天

class SuperClass { private int n; SuperClass(){ System.out.println("SuperClass()"); } SuperClass(int n) { System.out.println("SuperClass(int n)"); this.n = n; } } // SubClass 类继承 class SubClass extends SuperClass{ private int n; SubClass(){ // 自动调用父类的无参数构造器 System.out.println("SubClass"); } public SubClass(int n){ super(300); // 调用父类中带有参数的构造器 System.out.println("SubClass(int n):"+n); this.n = n; } } // SubClass2 类继承 class SubClass2 extends SuperClass{ private int n; SubClass2(){ super(300); // 调用父类中带有参数的构造器 System.out.println("SubClass2"); } public SubClass2(int n){ // 自动调用父类的无参数构造器 System.out.println("SubClass2(int n):"+n); this.n = n; } } public class TestSuperSub{ public static void main (String args[]){ System.out.println("------SubClass 类继承------"); SubClass sc1 = new SubClass(); SubClass sc2 = new SubClass(100); System.out.println("------SubClass2 类继承------"); SubClass2 sc3 = new SubClass2(); SubClass2 sc4 = new SubClass2(200); } }