CODEWITHSUNDEEP
javascriptjqueryregex
diya
diya

Reputation: 7148

Unable to validate hyphens

I'm trying to validate name which contains "alphanumeric characters, supported symbols, and space". Here I need to allow only a single hyphen(-), but not a double hyphen(--).

This is my code as follows:

$.validator.addMethod(
  'alphanumeric_only',
  function (val, elem) {
    return this.optional(elem) || /^[^*~<^>+(\--)/;|.]+$/.test(val);
  },
  $.format("shouldn't contain *.^~<>/;|")
);

The above code, doesn't even allow a single hyphen(-). How do I allow a single hyphen, but prevent a double hyphen. Any help is greatly appreciated.

Upvotes: 2

Views: 333

Answers (2)

core1024
core1024

Reputation: 1882

I advise you to use white list instead of blacklist. However this is working:

        <input type="text" id="validate"/>
    <script>
        $('#validate').keyup(function(){
            val = this.value;
            if(/([*.^~<>/;|]|--)/.test(val)) this.style.backgroundColor='red';
            else this.style.backgroundColor='';
        });
    </script>

Upvotes: 4

Tim Pietzcker
Tim Pietzcker

Reputation: 336468

For this, you need a negative lookahead assertion:

/^(?!.*--)[^*~<^>+()\/;|.]+$/

should do it.

Explanation:

^                 # Start of string
(?!               # Assert it's impossible to match the following:
 .*               #  any string, followed by
 --               #  two hyphens
)                 # End of lookahead
[^*~<^>+()\/;|.]+ # Match a string consisting only of characters other than these
$                 # End of string

Not that this might fail if your string can contain newlines. If it can, use

/^(?![\s\S]*--)[^*~<^>+()\/;|.]+$/

Upvotes: 6

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