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

by

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

More Related Contents:

  1. Find the highest number between two literal strings using a Regular Expression
  2. How to parse a string that contains value only needed partially to an arraylist? [closed]
  3. How to split a string, but also keep the delimiters?
  4. Match multiline text using regular expression
  5. Regex to match a C-style multiline comment
  6. Regex for matching something if it is not preceded by something else
  7. Splitting a string at every n-th character
  8. Parsing XML with REGEX in Java
  9. Java – Best way to grab ALL Strings between two Strings? (regex?)
  10. removing invalid XML characters from a string in java
  11. How do I convert CamelCase into human-readable names in Java?
  12. Replacing all non-alphanumeric characters with empty strings
  13. Extracting pairs of words using String.split()
  14. How to add features missing from the Java regex implementation?
  15. Is Java RegEx case-insensitive?
  16. Java String.split() sometimes giving blank strings
  17. Constructing regex pattern to match sentence
  18. pattern.matcher() vs pattern.matches()
  19. How to handle requests that includes forward slashes (/)?
  20. String.split() *not* on regular expression?
  21. java string split on all non-alphanumeric except apostrophes
  22. Find the first occurrence with Regex
  23. Java String ReplaceAll method giving illegal repetition error?
  24. Can java.util.regex.Pattern do partial matches?
  25. Find all words with 3 letters with regex
  26. What is a regex “independent non-capturing group”?
  27. Java regex error – Look-behind group does not have an obvious maximum length
  28. Parse Date from String in this format : dd/MM/yyyy [to dd/MM/yyyy]
  29. How can I perform a partial match with java.util.regex.*?
  30. Java replace all square brackets in a string

Leave a Comment