Java的传值方式

RisingGlass

一直以来 我一直都在想：Java到底是传值还是传引用
想不清楚，与舍友讨论结果是简单类型传值，object类型传引用，咋看上去好像没错，其实我觉得所有的类型都是传值，而没有传引用

测试代码如下：

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package javavaule;
/**
*
* @author duxingxia
*/
public class Main {
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        /*
         * test 1:Methos can't modify numeric paramenters
        */
        System.out.println("Testing tripleVaule:");
        double percent = 10;
        System.out.println("Before: percent="+percent);
        tripleValue(percent);
        System.out.println("After: percent="+percent);
        /*
         * test 2:Methods can change the state of object paramenters
        */
        System.out.println("\nTesting tripleSalary:");
        Employee harry = new Employee("Harry",50000);
        System.out.println("Before: salary="+harry.getSalary());
        tripleSalary(harry);
        System.out.println("After: salary="+harry.getSalary());
        /*
         * test 3:Methods can't attach new objects to object paramenters
        */
        System.out.println("\nTesting swap:");
        Employee a = new Employee("Alice",70000);
        Employee b = new Employee("Bod",60000);
        System.out.println("Before: a ="+a.getName());
        System.out.println("Before: b ="+b.getName());
        swap(a,b);
        System.out.println("After: a ="+a.getName());
        System.out.println("After: b ="+b.getName());
    }
    public static void tripleValue(double x)//doesn't work
    {
        x = 3 * x;
        System.out.println("End of Method: x=" + x);
    }
    public static void tripleSalary(Employee x)//works
    {
        x.raiseSalary(200);
        System.out.println("End of method: salary="+x.getSalary());
    }
    public static void swap(Employee a,Employee b)
    {
        Employee temp = a ;
        a = b;
        b = temp;
        System.out.println("End of method: a="+a.getName());
        System.out.println("End of method: b="+b.getName());
    }
}
class Employee
{
    public Employee(String n,double s)
    {
        name = n;
        salary = s;
    }
    public String getName()
    {
        return name;
    }
    public double getSalary()
    {
        return salary;
    }
    public void raiseSalary(double byPercent)
    {
        double raise = salary * byPercent / 100;
        salary += raise;
        return;
    }
    private String name;
    private double salary;
}
输出地截图如下：





本文来自ChinaUnix博客，如果查看原文请点：http://blog.chinaunix.net/u3/98826/showart_2113665.html