CODEWITHSUNDEEP
javascriptalgorithm
Roger González Hermosa
Roger González Hermosa

Reputation: 49

How do I find if a string has only letters, numbers and underscore characters?

I want to check if my string has only letters, numbers or underscore in it. I have this code

const str = 'test'

for (let i = 0; i < str.length; i++) {
  if (str.charAt(i) != /^(\w|_)+$/) {
    return false
  }
}

No matter what, it's always returning false although just introducing valid values.

Could anyone help?

Many thanks!

Upvotes: 1

Views: 214

Answers (1)

Tim Biegeleisen
Tim Biegeleisen

Reputation: 521979

Just use test() with the regex pattern ^\w+:

var str = 'test_here_123';
if (/^\w+$/.test(str)) {
    console.log("only letters, numbers, or underscore");
}

For reference, \w by definition matches letters, numbers, or underscore (which are collectively known as "word characters").

Upvotes: 4

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