第178題

Given:
1. public class Target{
2. private int i = 0;
3. public int addOne(){
4. return ++i;
5. }
6. }
And:

1. public class Client{
2. public static void main(String[] args){
3. System.out.println(new Target().addOne());
4. }
5. }

Which change can you make to Target without affecting Client?

A. Line 4 of class Target can be changed to return i++;
B. Line 2 of class Target can be changed to private int i = 1;
C. Line 3 of class Target can be changed to private int addOne(){
D. Line 2 of class Target can be changed to private Integer i = 0;

答案：D
參考：11-1 數字類型
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更改Target類別的內容也不會更改結果
D. Line 2 of class Target can be changed to private Integer i = 0; //會autoynboxing