JavaScript RegExp ignoreCase
Syntax & Examples

RegExp.ignoreCase property

The ignoreCase property of the RegExp object in JavaScript indicates whether the 'i' flag, which enables case-insensitive matching, is set. This property is read-only.

Syntax of RegExp.ignoreCase

The syntax of RegExp.ignoreCase property is:

RegExp.prototype.ignoreCase

This ignoreCase property of RegExp whether to ignore case while attempting a match in a string. This property is read-only.

Return Type

RegExp.ignoreCase returns value of type Boolean.


✐ Examples

1 Checking if the ignoreCase property is enabled

In JavaScript, we can check if the 'i' flag is enabled for a RegExp object by accessing the ignoreCase property.

For example,

  1. We create a RegExp object regex with the 'i' flag /abc/i.
  2. We check the ignoreCase property of regex to see if it is true.
  3. We log the result to the console.

JavaScript Program

const regex = /abc/i;
const isIgnoreCaseEnabled = regex.ignoreCase;
console.log(isIgnoreCaseEnabled);

Output

true

2 Comparing ignoreCase property with and without the 'i' flag

In JavaScript, we can compare the ignoreCase property of RegExp objects with and without the 'i' flag.

For example,

  1. We create a RegExp object regexWithI with the 'i' flag /abc/i.
  2. We create another RegExp object regexWithoutI without the 'i' flag /abc/.
  3. We check the ignoreCase property of both objects and log the results to the console.

JavaScript Program

const regexWithI = /abc/i;
const regexWithoutI = /abc/;
console.log(regexWithI.ignoreCase); // true
console.log(regexWithoutI.ignoreCase); // false

Output

true
false

3 Using ignoreCase property in conditional statements

In JavaScript, we can use the ignoreCase property in conditional statements to perform different actions based on whether the 'i' flag is enabled.

For example,

  1. We create a RegExp object regex with the 'i' flag /abc/i.
  2. We check the ignoreCase property of regex in an if statement.
  3. If the property is true, we log 'Case-insensitive matching is enabled.' to the console; otherwise, we log 'Case-insensitive matching is not enabled.'.

JavaScript Program

const regex = /abc/i;
if (regex.ignoreCase) {
  console.log('Case-insensitive matching is enabled.');
} else {
  console.log('Case-insensitive matching is not enabled.');
}

Output

Case-insensitive matching is enabled.

Summary

In this JavaScript tutorial, we learned about ignoreCase property of RegExp: the syntax and few working examples with output and detailed explanation for each example.