//输出结果是什么系列
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
class ValHold
{
public int i = 10;
}
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
public class ObParm
{
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public static void main(String argv[])
{
ObParm o = new ObParm();
o.amethod();
}
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public void amethod()
{
int i = 99;
ValHold v = new ValHold();
v.i=30;
another(v,i);
System.out.println(v.i);
}//End of amethod
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
public void another(ValHold v, int i)
{
i=0;
v.i = 20;
ValHold vh = new ValHold();
v = vh;
System.out.println(v.i+ " "+i);
}//End of another
}
![](/Images/OutliningIndicators/None.gif)
1) 10,0, 30
2) 20,0,30
3) 20,99,30
4) 10,0,20
![](/Images/OutliningIndicators/ContractedBlock.gif)
答案
10,0,20
![](/Images/OutliningIndicators/None.gif)
这个问题的核心是:引用类型的对像做为参数时,传递的是该对像内存地址的一个拷贝。
![](/Images/OutliningIndicators/None.gif)
知道了这一点。这题就不难啦!
张旋(zxsoft)
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