Home/ Questions/Q 9232291
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-18T06:16:46+00:00

I am trying to use a pattern check against a string, and for some

  • 0

I am trying to use a pattern check against a string, and for some reason it is saying that strings that shouldn’t match, do..

Code:

private static final Pattern VALID_TOKEN = Pattern.compile("^[a-zA-Z0-9\\{\\}\\[\\].+-/=><\\\\*]*$");
System.out.println(VALID_TOKEN.matcher(token).matches());

Examples:

"123" = true
"1,3" = true // Should NOT BE TRUE
"123*123" = true
"123*^123" = false

All of the above examples are correct except “1,3” the pattern should not include a COMMA. Does anyone have any ideas?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    You need to escape the dash in

    +-/

    Otherwise, it is interpreted as a range from '+' to '/' – a range that includes '+', ',', '-'. '.', and '/'.

    private static final Pattern VALID_TOKEN = Pattern.compile("^[a-zA-Z0-9\\{\\}\\[\\].+\\-/=><\\\\*]*$");
//                              Here ------------------------------------------------^^

    Alternatively, you can move the dash to the end of the character class (i.e. put it before the closing ]).

    • 0