java函数参数传值之我见
在一些群里总是有人问java函数传的到底是什么，这阵子有时间了，思考了一下，找了个演示小程序
又按自己的理解画了个图，如果有人光顾我的blog的话，可以讨论一下
class Obj
{
String str = "init value";
public String toString() //overiding重写了toString()方法,可以被显式或隐式调用
{
return str+"+Haha-yang";
}
}
public class ObjRef
{
Obj aObj = new Obj();
int aInt = 11;
public void changeObj(Obj inObj)
{
inObj.str = "changed value"; //可以改变传递进入对象的属性值
}
public void changePri(int inInt)
{
inInt = 22;
}
public static void main(String[] args)
{
ObjRef oRef = new ObjRef();
System.out.println("1 Before call changeObj() method: " + oRef.aObj);//在这里，oRef.aObj自动调用了Obj类的toString()方法（隐式调用）
System.out.println("2 Before call changeObj() method: " + oRef.aObj.toString());//在这里，oRef.aObj调用了Obj类的toString()方法（显式调用）
System.out.println("3 Before call changeObj() method: " + oRef.aObj.str);
oRef.changeObj(oRef.aObj);
System.out.println("4 After call changeObj() method: " + oRef.aObj);//oRef.aObj隐式调用了父类的toString()方法
System.out.println("4b After call changeObj() method: " + oRef.aObj.toString());//oRef.aObj显式调用了父类的toString()方法
System.out.println("3b Before call changeObj() method: " + oRef.aObj.str);
System.out.println("==================Print Primtive=================");
System.out.println("5 Before call changePri() method: " + oRef.aInt);
oRef.changePri(oRef.aInt);
System.out.println("6 After call changePri() method: " + oRef.aInt);
}
}
输出：
C:\123>java ObjRef
1 Before call changeObj() method: init value+Hahayang
2 Before call changeObj() method: init value+Hahayang
3 Before call changeObj() method: init value
4 After call changeObj() method: changed value+Hahayang
4b After call changeObj() method: changed value+Hahayang
3b Before call changeObj() method: changed value
==================Print Primtive=================
5 Before call changePri() method: 11
6 After call changePri() method: 11
