Java Script Regular expression for number format not working

Question

I want to get the input from the user as 888-999-6666..i.e. 3 numbers then a '-' then 3 numbers then again '-' and finally 4 numbers. I am using the following regular expression in my JavaScript.

     var num1=/^[0-9]{3}+-[0-9]{3}+-[0-9]{3}$/;
  if(!(form.num.value.match(num1)))
           {
           alert("Number cannot be left empty");
           return false;
           }

But its not working. If I use var num1=/^[0-9]+-[0-9]+-[0-9]$/; then it wants at least two '-' but no restriction on the numbers.

How can i get the RE as my requirement? And why is the above code not working?

var num1=/^[0-9]{3}+-[0-9]{3}+-[0-9]{3}$/; typo near last symbol class? Did you mean {4}? — Sergii Lagutin
– Sergii Lagutin, Commented Nov 6, 2014 at 10:44
@SergeyLagutin + after {} acts like a possessive quantifier which was supported by php but js won't — Avinash Raj
– Avinash Raj, Commented Nov 6, 2014 at 10:50

Avinash Raj · Accepted Answer · 2014-11-06 10:49:26Z

1

Remove the + symbol which are present just after to the repetition quantifier {} . And replace [0-9]{3} at the last with [0-9]{4}, so that it would allow exactly 4 digits after the last - symbol.

var num1=/^[0-9]{3}-[0-9]{3}-[0-9]{4}$/;

DEMO

You could also write [0-9] as \d.

edited Nov 6, 2014 at 10:49

answered Nov 6, 2014 at 10:44

Avinash Raj

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Comments

anubhava · Accepted Answer · 2014-11-06 10:44:28Z

0

Your regex should be:

var num1=/^[0-9]{3}-[0-9]{3}-[0-9]{4}$/;

There is an extra + after number range in your regex.

answered Nov 6, 2014 at 10:44

anubhava

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Bharat Ranpariya · Accepted Answer · 2014-11-06 11:05:11Z

0

Issue in your regex.check below example.

var num='888-999-6668';
var num1=/^[0-9]{3}-[0-9]{3}-[0-9]{4}$/;
  if(!(num.match(num1)))
   {
      alert("Number cannot be left empty");
   }else{
      alert("Match");
   }

In your example there is extra + symbole after {3}, which generate issue here. so i removed it and it worked.

edited Nov 6, 2014 at 11:05

answered Nov 6, 2014 at 10:49

Bharat Ranpariya

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monojit biswas · Accepted Answer · 2014-11-06 11:15:34Z

0

var num1=/^\d{3}-\d{3}-\d{4}$/;

I think this will work for you. The rest of your code will be the same.

answered Nov 6, 2014 at 11:15

monojit biswas

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