检查 Java \\$ 或 \\ 中的一组特定元字符，

Question

I need to check a specific set of the special characters: \\$ or \\, is present in String. Example;

  1) \\ghg$ : invalid
  2) \\ghg\\$ : valid
  3) ghg$ : invalid
  4) \\ghg\\,$ : invalid. Here $ is not escaped 
  5) ghg\\,\\$ : valid

Below is the code,

private static void regexValidation(String text, String pattern) {
        System.out.println(text + " and pattern " + pattern + " used" + ":" + text.matches(pattern) + " with pattern "
                + Pattern.compile(pattern).matcher(text).matches() + " with find "
                + Pattern.compile(pattern).matcher(text).find());
    }

The pattern used was pattern = ".*\\\\$.*"; which didnt give the expected result. Was using ".*\\\\B\\\\$\\\\B.*" but this also fails in the 4th case. Is there a way in java we can do filter the special character set?

Answer 1

seems your requirement is not very clear:

according to your \\$ or \\, , then \\\\ghg\\\\,$ should match, for it contain the \\\\, , which match \\,

so if your requirement is: match \\$ or \\, , then

• regex: ((\\\\\\$)|(\\\\,))
• match result (show in https://regexr.com ):
  • 

if you just want to test match or not, can use:

• regex: (((?<=\\\\)\\$)|(\\\\,))
• result:
  •