Replace backslash with double backslash [duplicate]

Question

I want to change the backslash in a string to double backslash.

I have

String path = "C:\Program Files\Text.txt";

and I want to change it to

"C:\\Program Files\\Text.txt"

Answer 1

replaceAll is using regex, and since you don't need to use regex here simply use

path = path.replace("\\", "\\\\");

\ is special in String literals. For instance it can be used to

• create special characters like tab \t, line separators \n \r,
• or to write characters using notation like \uXXXX (where X is hexadecimal value and XXXX represents position of character in Unicode Table).

To escape it (and create \ character) we need to add another \ before it.
So String literal representing \ character looks like "\\". String representing two \ characters looks like "\\\\".

Answer 2

Using String#replace()

String s= "C:\\Program Files\\Text.text";
System.out.println(s.replace("\\", "\\\\"));