Question

I have a file name which is stored in a String variable path.
I tried this:

path = path.replaceAll('\','/') 

but it does not work.

Answer 1

replaceAll() needs Strings as parameters.
So, if you write

path = path.replaceAll('\', '/');

it fails because you should have written

path = path.replaceAll("\", "/");

But this also fails because character ‘\’ should be typed ‘\\’.

path = path.replaceAll("\\", "/");

And this will fail during execution giving you a PatternSyntaxException, because the fisr String is a regular expression (Thanks @Bhavik Shah for pointing it out). So, writing it as a RegEx, as @jlordo gave in his answer:

path = path.replaceAll("\\\\", "/");

Is what you were looking for.

To make optimal your core, you should make it independent of the Operating System, so use @Thai Tran’s tip:

path = path.replaceAll("\\\\", File.separator);

But this fails throwing an StringIndexOutOfBoundsException (I don’t know why). It works if you use replace() with no regular expressions:

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