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How to Check Whether a String Does Not Start With a Regex in JavaScript

 2 years ago
source link: https://masteringjs.io/tutorials/fundamentals/regex-not-starting-with
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How to Check Whether a String Does Not Start With a Regex in JavaScript

Dec 29, 2021

To check if a string does not start with specific characters using a regular expression, use the test() function and negate it. Make sure your regular expression starts with ^, which is a special character that represents the start of the string.

function doesNotStartWithA(str) {
  return !/^A/.test(str);
}

Another approach is to use [^A]. [] denotes a set of characters to match, and ^ at the start of the set negates the set. So [^A] matches any character other than A.

function doesNotStartWithA(str) {
  return /^[^A]/.test(str);
}

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