Question

Is there a way to use str.charAt(index) to replace a specific char by index?
Something like this:

str.setCharAt(1,'X'); // replace 2nd char with 'X'

Is there any easy way to do that?

Answer 1

Depending on the source of str you may be able to do something like this:

StringBuilder str = new StringBuilder("Test string");
str.setCharAt(1, 'X');
str.toString();

If you have a string that you are piecing together and modifying a lot, it makes more sense to use a StringBuilder instead of a string. However, if you are modifying a String from another method call, the other answers may be more appropriate.