Issue
I have a string like s = "abc\def" and I want to replace "" with "/" and makes the string like "abc/def/".
I tried replaceAll("\\","/") but the compiler is giving error for string
error: illegal escape character
String s="abc\def";
Solution
The issue is that Java uses \ as the string escape character, but also as the regex escape character, and replaceAll performs a regex search. So you need to doubly escape the backslash (once to make it a literal \ in the string, and once to make it a literal character in the regular expression):
result = str.replaceAll("\\\\", "/");
Alternatively, you don’t actually need regular expressions here, so the following works as well:
result = str.replace("\\", "/");
Or, indeed, using the single-char replacement version:
result = str.replace('\\', '/');
Answered By – Konrad Rudolph
Answer Checked By – Gilberto Lyons (BugsFixing Admin)