java中的参数传递

为什么80%的码农都做不了架构师？>>>   

Java中方法参数传递是：值传递(Pass By Value)

public class ParameterDemo{
    public void changeValue1(int a){
        a = 8;
    }
    public void changeValue2(Employee e){
        e.salary = 8000;
    }
    public void changeValue3(Employee e){
        e = new Employee();
        e.salary = 8000;
    }
    public void swap(Employee e, Employee e2){
        Employee temp = e;
        e = e2;
        e2 = temp;
    }
 
    public static void main(String[] args){
        MethodDemo m = new MethodDemo();
        
        int a = 10;
        System.out.println(a);//10
        m.changeValue1(a);
        System.out.println(a);//10
        
        Employee e = new Employee();
        System.out.println(e.salary);//0
        m.changeValue2(e);
        System.out.println(e.salary);//8000
        Employee e2 = new Employee();
        System.out.println(e2.salary);//0
        m.changeValue3(e2);
        System.out.println(e2.salary);//0
        Employee e3 = new Employee();
        e3.name = "huhu";
        Employee e4 = new Employee();
        e4.name = "hengheng";
        System.out.println("e3.name = "+e3.name+" e4.name = "+ e4.name);//e3.name = huhu e4.name = hengheng
        m.swap(e3, e4);
        System.out.println("e3.name = "+e3.name+" e4.name = "+ e4.name);//e3.name = huhu e4.name = hengheng
    }
}
class Employee{
    String name;
    int salary;
}

转载于:https://my.oschina.net/tashi/blog/186917