CODEWITHSUNDEEP
regexflutterdart
blue492
blue492

Reputation: 670

RegExp for numbers 024648-4568 in dart

I am using Flutter and dart and I want RegExp to validate strings in the 024648-4568 like format, where a user can only put six numbers at the start, then a - and then 4 digits at the end.

I started with RegExp(r'^\d{1,6}[\-]?\d{4}'), but could not fix it for the subsequent dash and 4 digits.

In Flutter, I use it like this:

inputFormatters: [new FilteringTextInputFormatter.allow( RegExp(r'^\d{1,6}-\d{4}') ,]

Upvotes: 1

Views: 2636

Answers (1)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626903

You need to make sure the regular expression you use in the FilteringTextInputFormatter can match a zero- or one-char length string. For example, you can use

RegExp(r'^\d{1,6}(?:-\d{0,4})?$')

See the regex demo. The {1,6} limiting quantifier makes the first digit required in the input.

More details:

  • ^ - start of string
  • \d{1,6} - one to six digits
  • (?:-\d{0,4})? - an optional sequence of
    • - - a hyphen
    • \d{0,4} - zero to four digits
  • $ - end of string.

Upvotes: 3

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