replace a single quote in a string with another single quote

Question

I have a String with single quote. I want to replace the single quote with 2 single quotes. I tried using

 String s="Kathleen D'Souza";

s.replaceAll("'","''");

s.replaceAll("\'","\'\'");

s.replace("'","''");

s.replace("\'","\'\'");

But the single quote is not getting replaced with 2 single quotes.

Answer 1

reassign the replaced string to s

String s="Kathleen D'Souza";
s = s.replaceAll("'","''");

Answer 2

Please try s= "test ' test";

`s.replaceAll("'","\"");`     => test " test

`s.replaceAll("'","''");`     => test '' test