Regex: How to check if a string is not empty or blank and does not contain the character "<" and ">"?

Question

I have to use a regex to verify if a string is not empty or blank, and doesn't contain ">" "<".

For example:

1. " " is invalid;

2. " a <" is invalid;

3. " a 6" is OK;

I tried below regex, but doesn't work.

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^(^\s*$)|^[^<,>]+$

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How could I set this regex? could any kind guys help me on this? thanks.

Answer 1

Try

^(?!\s+$)[^<>]+$

• ^...$ - String should start and end with... (matching whole string/line)
  • (?!...) - Negative lookahead, string should not be followed by...
    • \s+$ - One or more whitespace characters until the end of the string
  • [^<>]+ - Any character except < and >, one or more times

Live demo