Petar Ivanov 对在字符串问题中替换特定索引处的字符

字符串在Java中是不可变的。您不能更改它们。

String are immutable in Java. You can't change them.

您需要创建一个替换了字符的新字符串。

You need to create a new string with the character replaced.

String myName = "domanokz";
String newName = myName.substring(0,4)+'x'+myName.substring(5);

或者你可以使用StringBuilder：

Or you can use a StringBuilder:

StringBuilder myName = new StringBuilder("domanokz");
myName.setCharAt(4, 'x');

System.out.println(myName);