CODEWITHSUNDEEP
javascriptregex
Shah
Shah

Reputation: 5018

regex to detect leading zeros and check the lenght from 0 to 12 digits

Hi I have a javascript function that checks for signed integer with 0 to 12 length, i also want to see if there are any leading 0's like 0012 should return false.

function sInteger0to12(str) {
    str = str.replace(/^\s+|\s+$/g, '');
    return /^[-+]?\d{0,12}$/.test(str);
}

any help will be appreciated.

Upvotes: 1

Views: 2674

Answers (4)

cezary
cezary

Reputation: 1

This should help:

/(^0$)|(^[+-]?[1-9]\d{0,11}$)/

Upvotes: 0

Andrew Cox
Andrew Cox

Reputation: 10998

You need to cover three cases

  1. an empty string
  2. a single 0
  3. a no zero padded 1 to 12 digit number

these cases equate to

  1. ^$
  2. ^0$
  3. ^[+-]?[1-9]\d{0,11}$

which adds up to

^()|(0)|([+-]?[1-9]\d{0,11})$

Upvotes: 0

Mark Byers
Mark Byers

Reputation: 838916

I'm assuming that the following should match:

1
+1
-1
0
-123456789012
<empty>

And these should fail:

-
+
01
-01
1234567890123
00
+0
-0

If you disagree with my decisions above, please let me know and I will try to fix the regex.

Here's a regex you can use:

/^([-+]?[1-9]\d{,11}|0)?$/

Upvotes: 6

SLaks
SLaks

Reputation: 887887

Like this:

 /^[-+]?[1-9]\d{0,11}$/

You'll need to check for '0' separately.

Upvotes: 1

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