intern()返回值错误

[YPEU]

P114页，8.12.1（常量池中已存在字符串）
以下代码的执行结果：
书上：false，true
idea(JDK8，JDK21):false，false
`
@test
public void internTest(){
String s1 = new String("1");
s1.intern();
String s2 = "1";
System.out.println("s1 == s2 : " + (s1 == s2));

    System.out.println("=========================");

    String s3 = "1" + "1";
    s3.intern();
    String s4 = "11";
    System.out.println("s3 == s4 : " + (s3 == s4));

}

`

修正代码：
s3.intern()——>s3 = s3.intern()；
`
@test
public void internTest(){
String s1 = new String("1");
s1.intern();
String s2 = "1";
System.out.println("s1 == s2 : " + (s1 == s2));

    System.out.println("=========================");

    String s3 = "1" + "1";
    s3 = s3.intern();
    String s4 = "11";
    System.out.println("s3 == s4 : " + (s3 == s4));

}

`
此时打印结果为：true false