29 String Methods in JavaScript

Photo by James Harrison on Unsplash

JavaScript string methods are built-in functions that can be called on a string to perform operations and manipulate the string. These methods allow developers to work with strings in a more efficient and intuitive way.

Further Js has 29 string methods. Let’s explore all of them.

charAt() - Returns the character at the specified index in a string.

let str = "hello";
console.log(str.charAt(1)); // "e"

charCodeAt() - Returns the Unicode value of the character at the specified index in a string.

let str = "hello";
console.log(str.charCodeAt(1)); // 101 (the Unicode value for "e")

concat() - Joins two or more strings and returns a new string.

let str1 = "hello";
let str2 = "world";
console.log(str1.concat(" ", str2)); // "hello world"

endsWith() - Returns a Boolean indicating whether the string ends with the specified character(s).

let str = "hello world";
console.log(str.endsWith("world")); // true

includes() - Returns a Boolean indicating whether the string contains the specified character(s).

let str = "hello world";
console.log(str.includes("world")); // true

indexOf() - Returns the index of the first occurrence of the specified character(s) in a string.

let str = "hello world";
console.log(str.indexOf("o")); // 4

lastIndexOf() - Returns the index of the last occurrence of the specified character(s) in a string.

let str = "hello world";
console.log(str.lastIndexOf("o")); // 7

localeCompare() - Compares two strings in the current locale and returns a number indicating their relative position.

let str1 = "apple";
let str2 = "banana";
console.log(str1.localeCompare(str2)); // -1 (because "apple" comes before "banana" in alphabetical order)

match() - Searches a string for a match against a regular expression and returns an array of matches.

let str = "The quick brown fox jumps over the lazy dog.";
let regex = /[A-Z]/g;
console.log(str.match(regex)); // ["T", "B", "F"]

normalize() - Returns a Unicode Normalization Form of a given string.

let str = "M\u0301xico";
console.log(str.normalize()); // "México"

padEnd() - Pads the end of a string with a specified character until it reaches a specified length.

let str = "hello";
console.log(str.padEnd(10, ".")); // "hello....."

padStart() - Pads the beginning of a string with a specified character until it reaches a specified length.

let str = "hello";
console.log(str.padStart(10, ".")); // ".....hello"

repeat() - Returns a new string with a specified number of copies of an existing string.

let str = "hello";
console.log(str.repeat(3)); // "hellohellohello"

replace() - Searches a string for a specified value and returns a new string with the value replaced.

let str = "hello world";
console.log(str.replace("world", "mars")); // "hello mars"

search() - Searches a string for a specified value and returns the position of the match.

const str = 'The quick brown fox jumps over the lazy dog.';

console.log(str.search('brown')); // 10
console.log(str.search(/cat/g)); // -1

slice() - Extracts a section of a string and returns a new string.

const str = 'The quick brown fox jumps over the lazy dog.';
console.log(str.slice(4, 9)); // "quick"

split() - Splits a string into an array of substrings.

const str = 'The quick brown fox jumps over the lazy dog.';

console.log(str.split(' ')); // ["The", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog."]
console.log(str.split('o')); // ["The quick br", "wn f", "x jumps ", "ver the lazy d", "g."]

startsWith() - Returns a Boolean indicating whether the string starts with the specified character(s).

const str = 'Hello World!';
const startsWithHello = str.startsWith('Hello');
const startsWithWorld = str.startsWith('World');

console.log(startsWithHello); // Output: true
console.log(startsWithWorld); // Output: false

substr() - Extracts a specified number of characters from a string, starting at a specified index.

const str = 'The quick brown fox jumps over the lazy dog.';
console.log(str.substr(4, 5)); // "quick"

substring() - Extracts the characters between two specified indices in a string.

const str = 'The quick brown fox jumps over the lazy dog.';
console.log(str.substring(4, 9)); // "quick"

toLocaleLowerCase() - Converts a string to lowercase in the current locale.

const str = 'HELLO';
console.log(str.toLocaleLowerCase()); // "hello"

toLocaleUpperCase() - Converts a string to uppercase in the current locale.

const str = 'hello';
console.log(str.toLocaleUpperCase()); // "HELLO"

toLowerCase() - Converts a string to lowercase.

const str = 'HELLO';
console.log(str.toLowerCase()); // "hello"

toString() - Returns a string representation of an object.

const num = 123;
console.log(num.toString()); // "123"

toUpperCase() - Converts a string to uppercase.

const str = 'hello';
console.log(str.toUpperCase()); // "HELLO"

trim() - Removes whitespace from both ends of a string.

const str = '  Hello World   ';
console.log(str.trim()); // "Hello World"

trimEnd() - Removes whitespace from the end of a string.

const str = '   Hello World!   ';
const trimmedStr = str.trimEnd();

console.log(trimmedStr); // Output: '   Hello World!'

trimStart() - Removes whitespace from the beginning of a string.

const str = '   Hello World!   ';
const trimmedStr = str.trimStart();

console.log(trimmedStr); // Output: 'Hello World!   '

valueOf() - Returns the primitive value of an object.

const strObj = new String('Hello World!');
const primitiveValue = strObj.valueOf();

console.log(primitiveValue); // Output: 'Hello World!'

Thanks for reading ❤️