Trying to check input against a regular expression.
The field should only allow alphanumeric characters, dashes and underscores and should NOT allow spaces.
However, the code below allows spaces.
What am I missing?
var regexp = /^[a-zA-Z0-9\-\_]$/;
var check = "checkme";
if (check.search(regexp) == -1)
{ alert('invalid'); }
else
{ alert('valid'); }
Thanks in advance.
Solution
However, the code below allows spaces.
No, it doesn’t. However, it will only match on input with a length of 1. For inputs with a length greater than or equal to 1, you need a + following the character class:
var regexp = /^[a-zA-Z0-9-_]+$/;
var check = "checkme";
if (check.search(regexp) == -1)
{ alert('invalid'); }
else
{ alert('valid'); }
Note that neither the - (in this instance) nor the _ need escaping.
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