No, the additional '\' is required only when you are using a special character within a string in the code. For example, "\\t is for tab". If you don't put \\ here, you will get " is for tab".
What? It runs fine with a single '\' in this statement for example:
you can use single '\' for special characters like b t n r " ' \
Only for regex you need to escape the '\' because '\s' is required for example but in
Java String you need to escape '\' with '\' hence the String will be '\\s'.
Hope I'm not wrong.