Java基础

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public class Test {

    public Test() {
    }

    public void aMethod() {   
        Base v = new Base();
        System.out.println("v.x = " + v.x);  //1
        bMethod(v);
        System.out.println("v.x = " + v.x);  //6
    }
 
    public void bMethod(Base v) {
        v.x = 6;
        Base vh = new Base();
        v = vh;
        System.out.println("v.x = " + v.x);   //1    
    }

    public static void main(String[] args) {
        Test tst=new Test();
        tst.aMethod();       
       
        Base vv=new SubBase();
        System.out.println("vv.x = " + vv.x);  //1 域的隐藏
        System.out.println("run vv.method() = " + vv.method());   //2 方法的覆盖     
          
    }
   
}

class Base {
 
    int x = 1;
   
    int method() {
        return x;
    }
   
}

class SubBase extends Base {
   
 int x = 2;
 
    int method() {   
        return x;
    }
   
}

结果：
v.x = 1
v.x = 1
v.x = 6
vv.x = 1
run vv.method() = 2