class FatherClass{ 
  public int value; 
  public void f(){ 
    value=100; 
    System.out.println 
    ("FatherClass.value:"+value); 
  } 
} 
 
 
class ChildClass extends FatherClass{ 
  public int value; 
  public void f(){ 
    super.f(); 
    value=200; 
    System.out.println 
    ("ChildClass.value:"+value); 
    System.out.println(value); 
    System.out.println(super.value); 
  } 
} 
 
 
public class test1 { 
  public static void main(String[] args){ 
    ChildClass cc=new ChildClass(); 
    cc.f(); 
  } 
} 

FatherClass.value:100
ChildClass.value:200
200
100

class SuperClass{ 
  private int n; 
   
  SuperClass(){ 
    System.out.println("調(diào)用SuperClass()"); 
  } 
  SuperClass(int n){ 
      System.out.println("調(diào)用SuperClass("+n+")"); 
    } 
} 
 
class SubClass extends SuperClass{ 
  private int n; 
   
  SubClass(int n){ 
     
    //當(dāng)子類(lèi)的構(gòu)造方法中沒(méi)有寫(xiě)super的時(shí)候，系統(tǒng)默認(rèn)的調(diào)用父類(lèi)的沒(méi)有參數(shù)的構(gòu)造方法 
    //相當(dāng)于此處寫(xiě)了如下: 
    //super(); 
     
    System.out.println("調(diào)用SuberClass("+n+")"); 
    this.n=n; 
  } 
   
  SubClass(){ 
    super(300); 
    //在子類(lèi)構(gòu)造過(guò)程當(dāng)中必須調(diào)用父類(lèi)構(gòu)造方法,并且super必須寫(xiě)在第一句（先有爸爸再有兒子） 
     
    System.out.println("調(diào)用SubClass()"); 
  } 
} 
public class test2 { 
  public static void main(String[] args){ 
    SubClass sc1=new SubClass(); 
     
    SubClass sc2=new SubClass(400); 
     
  } 
} 

調(diào)用SuperClass(300)
調(diào)用SubClass()
調(diào)用SuperClass()
調(diào)用SuberClass(400)