Object Oriented Practice Questions



   public class DifficultTest { 
      public static void main(String[] args) {  
       System.out.println(new B().getValue());                             
      } 
      static class A {  
           protected int value;  
           public A(int v) {      
            System.out.println("public A(int v)执行了");
            setValue(v); 
       }  
       public void setValue(int value) {   
            System.out.println("AsetValue(int Value)执行了"); 
            this.value = value; 
       }  
       public int getValue() {      
            System.out.println("AgetValue()执行了"); 
            try {    
                 value++; 
                 return value; //Execute the result returned by getValue
            } finally { //finally is a certain block
                 setValue(value);
                 System.out.println(value);
            }  
           } 
      } 
  static class B extends A {  
        public B() { / /subclass this   
        super(5);
        setValue(getValue() - 3); 
        System.out.println("public B() executed");  
       }  
       public void setValue(int value) { 
            super.setValue(2 * value); 
            System.out.println("BsetValue(int value) executed");  
           } 
      }
 }

 The returned result is:

public A(int v) executed v=5
 * AsetValue(int Value) executed v=10
 * BsetValue(int value) executed v=10
 * AgetValue() executed v=11
 * AsetValue(int Value) executed v=22
 * BsetValue(int value) executes v=22
 * 22 (getValue returns a value of 11)
 * AsetValue(int Value) executes v=16
 * BsetValue(int value) executes v=16
 * public B( ) executed v=16
 * AgetValue() executed v=17
 * AsetValue(int Value) executed v=34
 * BsetValue(int value) executed v=34
 * 34
 * 17 (getValue returns the value of 17)