Java 为什么盗窃.getTime（）[0]=“0”；aaa“+；thift.getTimie（）[0]don'；你不能改变这个值吗？

跑步时

public class Theft{
  private String[] time =new String[4];
  public String[] getTime() {
    return time = Arrays.copyOf(time, 4);
  }

  public void setTime(String[] time) {
    this.time = time;
  }
}

---

为什么打印“sss”而不是“aaasss”？该值似乎没有更改。

因为您每次都要创建它的副本

Theft theft =new Theft();
theft.getTime()[0]="sss";
theft.getTime()[0]="aaa"+theft.getTime()[0];
System.out.println(theft.getTime()[0]);

输出：

aaasss

此行

public class Theft {
    private String[] time = new String[4];

    public String[] getTime() {
        return time; // Return the time itself, not a copy
    }

    public void setTime(String[] time) {
        this.time = time;
    }
}

一次发生几件事。让我们将其分解为单独的说明，以便更易于遵循：

theft.getTime()[0]="aaa"+theft.getTime()[0];

如您所见，更新的数组是已被其副本替换的

time1

。因此，更新被有效地丢弃

String[] time1 = theft.getTime();
String[] time2 = theft.getTime();
String newValue = "aaa"+time2[0];
time1[0] = newValue;