#How to #JS #Regex

Recently, I came across a code challenge to find the number of occurrences of a character in a string.

It was intended to use it as a validator in order to perform some minimum char length along with the occurrences.

Anyhow, it took some time to figure out a way using Regex.

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searchString
  // split into each characters.
  .split('')
  // Sort it so that the similar chars can be grouped together.
  .sort()
  // Join them to group.
  .join('')
  // match the chars those have more than one occurrence.
  .match(/(.)\1+/g)
  // Do what you wish with the result. I am just counting the length here.
  .map((a) => a.length);

Tip: Try to modify the Regex to match only a set of chars occurrences.

#How to #JS #Regex