CODEWITHSUNDEEP
javascriptregexreactjs
henhen
henhen

Reputation: 1205

Input box onchange only allow numbers and one dot

I am creating an input box with an onChange function that will check to see if the characters are only digits and only allow up to one period/dot '.'

The function I have here is not working:

function addPercentSeparator(n) {
  let str = n;
  let match = str.match(/\d*\.\d*/)
  if (match) {
    return str;
  }
}

I also tried: let match = str.match(/^([0-9]+(\.[0-9]+)?)/)

What I am trying to achieve is only allowing for one period. If the user enters a number without a period, it will append a period to end of string when they click outside the input box.

Upvotes: 0

Views: 419

Answers (1)

GalAbra
GalAbra

Reputation: 5148

This regex is supposed to do the trick:

^\d*\.?\d*$

But if you'll ask me, I would make sure there are digits before the dot, using ^\d+\.?\d*$.


Explanation:

  • As the dot isn't mandatory, I've added the ?, which symbolizes "0 or 1 occurrences".
  • I've also added the ^ and the $ to make sure no parts of the string will be matched if the whole string is illegal.

I hope this works for you!

Upvotes: 1

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