Why does this Java regex cause “illegal escape character” errors?

Question

I\'m working on a solution to a previous question, as best as I can, using regular expressions. My pattern is

\"\\d{4}\\w{3}(0[1-9]|[12][0-9]|3[01])([01][0-         


        

Answer 1

I think you need to add the two escaped shortcuts into character classes. Try this: "[\d]{4}[\w]{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}"

--Good Luck.

Answer 2

Have you tried this?

\\d{4}\\w{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}

Answer 3

Assuming this regex is inside a Java String literal, you need to escape the backslashes for your \d and \w tags:

"\\d{4}\\w{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}"

This gets more, well, bonkers frankly, when you want to match backslashes:

public static void main(String[] args) {        
    Pattern p = Pattern.compile("\\\\\\\\"); //ERM, YEP: 8 OF THEM
    String s = "\\\\";
    Matcher m = p.matcher(s);
    System.out.println(s);
    System.out.println(m.matches());
}

\\ //JUST TO MATCH TWO SLASHES :(
true

Answer 4

Did you try "\\d" and "\\w"?

-edit- Lol I posted the right answer and get down voted and then I notice that stackoverflow escapes backslashes so my answer appeared wrong :)

Answer 5

all you need to do is to put

 *\
 ex: string ex = 'this is the character: *\\s';

before your invalid character and not 8 \ !!!!!

Answer 6

What about the following: \\d{4}\\w{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}