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this关键字

总结:
1.调用构造器
2.引用成员数据
3.返回当前对象的句柄

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public class Flower {
private int petalCount = 0;
private String s = new String("null");
Flower(int petals){
petalCount = petals;
}
Flower(String ss){
s = ss;
}
Flower(String ss, int petals){
this(petals); //this的一种用法
//this(ss); //可用this调用一个构造器,但不能调用两个
this.s = ss; //this的另一种用法
}
Flower(){
this("hi",47);//使用默认无参构造器实现初始化;
}
}

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public class Leaf {
private int i = 0;
Leaf increment(){
i++;
return this;//返回当前对象的句柄
}
void print(){
System.out.println("i = " + i);
}

public static void main(String[] args){
Leaf x = new Leaf();
x.increment().increment().increment().print();//out: i = 3
}
}