How do I perform a JavaScript ignore case string comparison?

General Discussions
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1

I want to compare two strings without considering their case in JavaScript. What’s the best way to do this?

2

Hi bro! try String.prototype.toLowerCase() by this you can convert both strings to lowercase using toLowerCase() and then compare them. This approach is simple and works well for most cases.

let str1 = "Hello";
let str2 = "hello";

if (str1.toLowerCase() === str2.toLowerCase()) {
console.log("The strings are equal (case-insensitive).");
} else {
console.log("The strings are not equal.");
}

Well, toLowerCase() converts both strings to lowercase before the comparison, making it case-insensitive.

3

I see there is already one answer for the question but for more advanced scenarios, Using a Regular Expression with i Flag would be beneficial, especially when you need to perform case-insensitive pattern matching, you can use this.

let str1 = "Hello";
let str2 = "hello";

let regex = new RegExp("^" + str2 + "$", "i");

if (regex.test(str1)) {
console.log("The strings are equal (case-insensitive).");
} else {
console.log("The strings are not equal.");
}

In this, the regular expression ^${str2}$ matches the entire string, and the i flag ensures the comparison is case-insensitive.

4

Greeting! I may be the last to answer but I surely won’t disappoint. I will keep it simple. Use String.prototype.toUpperCase() Similar to toLowerCase(), you can convert both strings to uppercase using toUpperCase(). The comparison will then be case-insensitive.

javascript Copy Edit

let str1 = "Hello";
let str2 = "HELLO";

if (str1.toUpperCase() === str2.toUpperCase()) {
console.log("The strings are equal (case-insensitive).");
} else {
console.log("The strings are not equal.");
}

toUpperCase() works the same way as toLowerCase() but converts the strings to uppercase before comparison.