String.replace result is ignored?

Question

So i\'m using IntelliJ and the replace buzzword is highlighted. Most of the tips are over my head so i ignore them, but what i got for this one was that the result of string

Answer 1

String objects are immutable.

From the docs:

public String replace(char oldChar,char newChar)

Returns a string resulting from replacing all occurrences of oldChar in this string with newChar.

Hope this helps.