Java基础之值传递 引用传递

示例一：值传递
public class ValueDemo{
	public static void main(String[] args){
		int x = 10;
		method(x) ;
		System.out.println(“x=”+x) ;
	}
	public static void method(int mx){
		mx = 20;
	}
}

示例二：引用传递
public class RefDemo1{
	public static void main(String[] args){
		Duck d  = new Duck();
		method(d) ;
		System.out.println(“Duck age = ”+d.age) ;
	}
	public static void method(Duck duck){
		duck.age = 5;
	}
}
class Duck{
 	int age = 2;   //省略封装
}

示例三：String传递
字符串本身就是一个对象
public class RefDemo2{
	public static void main(String[] args){
		String name = “小飞”;
		method(name) ;
		System.out.println(“name=”+name) ;
	}
	public static void method(String sname){
		sname = “小备”;
	}
}

示例四：String传递
public class RefDemo3{
	public static void main(String[] args){
		Person p  = new Person();
		method(p) ;
		System.out.println(“person name= ”+p.name) ;
	}
	public static void method(Person per ){
		per.name = “备备”;
	}
}
class Person{
 	String name = “飞飞”;   //省略封装
}