Case insensitive regex in JavaScript

user_147613 0
Viewed 123502

I want to extract a query string from my URL using JavaScript, and I want to do a case insensitive comparison for the query string name. Here is what I am doing:

var results = new RegExp('[\\?&]' + name + '=([^&#]*)').exec(window.location.href);
if (!results) { return 0; }
return results[1] || 0;

But the above code does a case sensitive search. I tried /<regex>/i but it did not help. Any idea how can that be achieved?

javascript regex
5 Answers

Simple one liner. In the example below it replaces every vowel with an X.

function replaceWithRegex(str, regex, replaceWith) {
  return str.replace(regex, replaceWith);
}

replaceWithRegex('HEllo there', /[aeiou]/gi, 'X'); //"HXllX thXrX"
user_47810670

Just an alternative suggestion: when you find yourself reaching for "case insensitive regex", you can usually accomplish the same by just manipulating the case of the strings you are comparing:

const foo = 'HellO, WoRlD!';
const isFoo = 'hello, world!';
return foo.toLowerCase() === isFoo.toLowerCase();

I would also call this easier to read and grok the author's intent!

user_25170330

For example to search word date, upper or lowercase you need to add param i

i = means incasesensitive

example

const value = "some text with dAtE";
/date/i.test(value)

or

const value = "some text with dAtE";
 new RegExp("/date/","i");
user_100941670
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