Case-insensitive substring search

JavaScript, String · Jul 28, 2022

Checks if a string contains a substring, case-insensitive.

  • Use the RegExp constructor with the 'i' flag to create a regular expression, that matches the given searchString, ignoring the case.
  • Use RegExp.prototype.test() to check if the string contains the substring.
const includesCaseInsensitive = (str, searchString) =>
  new RegExp(searchString, 'i').test(str);
includesCaseInsensitive('Blue Whale', 'blue'); // true

Written by Angelos Chalaris

I'm Angelos Chalaris, a JavaScript software engineer, based in Athens, Greece. The best snippets from my coding adventures are published here to help others learn to code.

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