有人可以解釋爲什麼我的預期結果和實際結果有所不同。反映實際對象的Java本地對象副本
我已經在各種網站(包括計算器)中經歷了一些其他帖子,但答案並未切入點。
public class Test
{
List<String> str= new ArrayList<String>();
public void addString(String a)
{
str.add(a);
}
public void takeALocalCopy(Test c)
{
Test localCopy1= c;
localCopy1.addString("Two");
//Expecting output -->One,Two -->Success.
System.out.println(localCopy1.toString());
Test localCopy2= c;
localCopy2.addString("Three");
//Expecting -->One,Three but actual is One,Two,Three.
System.out.println(localCopy2.toString());
}
@Override
public String toString() {
return "Test [str=" + str + "]";
}
public static void main(String[] args)
{
Test c= new Test();
c.addString("One");
c.takeALocalCopy(c);
}
}
OUTPUT:
Test [str=[One, Two]]
Test [str=[One, Two, Three]] //Expected One, Two
你是否明白所有這些變量都是**引用**? – 2014-10-01 22:29:01