CODEWITHSUNDEEP
regex
Varada
Varada

Reputation: 17062

regex is allowing character while using \s

How do I write a regular expression for checking if the entered value are all white space or empty or digits. In all other cases it will return false. I tried \s*|\d+ which is allowing character values too.

Upvotes: 2

Views: 42

Answers (1)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 627100

Your regex \s*|\d+ just matches 0 or more whitespace or 1 or more digits anywhere inside an input string and it may contain whitespace mixed with digits and other characters.

You can use the following regex:

^(?:\s+|\d+)?$

See demo

The regex matches:

  • ^ - start of string
  • (?:\s+|\d+)? - 1 or 0 occurrences (due to (?:...)?) of...
    • \s+ - 1 or more whitespace symbols or
    • \d+ - 1 or more digits
  • $ - end of string

In plain human words,

  • ^....$ - make sure we require a full string match, any partial matches inside a string are not allowed
  • (?:...)? - all the texts matched with the subpatterns inside this group are optional, thus allowing an empty string match (i.e. return true if the string is empty).

Upvotes: 3

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