CODEWITHSUNDEEP
javascriptregex
SilverWolf
SilverWolf

Reputation: 3

RegEx to match a binary number with even number of 0s

I'm working to create a regex to match a binaries with an even number of zeros.

For example, it should match numbers like:

001
1010
100100

But it shouldn't match:

0010
10001
00101

This is what I have so far:

(([0]{1})+)

I will really highly appreciate any help on this.

Upvotes: 0

Views: 310

Answers (1)

Nick
Nick

Reputation: 147156

Although not the best way, you can use a regex for this, searching for pairs of 0's in the string and asserting that there are no other 0 characters in the string outside those pairs (thus there must be an even number of 0's):

^(?:[^0]*0[^0]*0)+[^0]*$


const strs = [
  '1010',
  '100100',
  '0010',
  '10001',
  '00101',
  '001',
  '1001',
  '100',
  '101'
]

strs.map(s => console.log(s + ': ' + /^(?:[^0]*0[^0]*0)+[^0]*$/.test(s)));

Upvotes: 1

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