Java 继承中的构造方法

class SuperClass {
    private int n;


    SuperClass() {
        System.out.println("SuperClass()");
    }


    SuperClass(int n){
        System.out.println("SuperClass(" + n + ")");
        this.n = n;
    }
}

class SubClass extends SuperClass {
    private int n;

    SubClass(int n) {
            //super();

        System.out.println("SubClass(" + n +")");
        this.n =n;
    }

    SubClass() {
            super(300);
        System.out.println("SubClass()");
    }
}

public class TestSuperSub {
 public static void main(String arg[]) {
    //SubClass sc1 = new SubClass();

    SubClass sc2 = new SubClass(400);
 }
}