JavaScript RegExp i Modifier

Do a case-insensitive serch for "is":

let text = "Visit W3Schools";
let pattern = /w3schools/i;
let result = text.match(pattern);

Description

The "i" modifier specifies a case-insenitive match.

/regexp/i is an ECMAScript1 (ES1) feature.

ES1 (JavaScript 1997) is fully supported in all browsers:


Chrome	Edge	Firefox	Safari	Opera	IE
Yes	Yes	Yes	Yes	Yes	Yes

new RegExp("regexp", "i")

or simply:

/regexp/i

Do a case-insensitive search for "w3schools" in a string:

Using the RegExp function exec()::

let text = "Visit W3Schools";
let pattern = /w3schools/i;
let result = pattern.exec(text);

Using the RegExp function test()::

let text = "Visit W3Schools";
let pattern = /w3schools/i;
let result = pattern.test(text);

Using the String function match():

let text = "Visit W3Schools";
let pattern = /w3schools/i;
let result = text.match(pattern);

You can use the ignoreCase property to check if the "i" modifier is set.

let pattern = /W3S/i;
let result = pattern.ignoreCase;

In JavaScript, a regular expression text search, can be done with different methods.

With a pattern as a regular expression, these are the most common methods: