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JavaScript String Methods cheat sheet

JavaScript String Methods cheat sheet. Explore our ultimate quick reference for JavaScript String Methods.

Welcome to this comprehensive cheat sheet covering 38 JavaScript string methods, categorized for easy reference. Whether you're a beginner or an experienced developer, you'll find clear explanations and examples to enhance your coding efficiency. For further reading and detailed documentation, visit the MDN Web Docs. Happy coding!

Creation Methods

fromCharCode()

Creates a string from a sequence of Unicode values.

console.log(String.fromCharCode(65, 66, 67)); // "ABC"

fromCodePoint()

Creates a string from a sequence of code points.

console.log(String.fromCodePoint(9731, 9733, 9734)); // "☃★☆"

raw()

Creates a raw string from a template string.

console.log(String.raw`Hello\nWorld`); // "Hello\nWorld"

Accessor Methods

String[@@iterator]()

Returns a new Iterator object that iterates over the code points of a string.

const str = 'hello';
const iterator = str[Symbol.iterator]();
console.log(iterator.next().value); // "h"

at()

Returns the character at the given index, allowing for positive and negative integers.

const str = 'hello';
console.log(str.at(-1)); // "o"

charAt()

Returns the character at the specified index.

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

charCodeAt()

Returns the Unicode value of the character at the specified index.

const str = 'hello';
console.log(str.charCodeAt(1)); // 101

codePointAt()

Returns the code point value of the character at the specified index.

const str = 'hello';
console.log(str.codePointAt(1)); // 101

Transformation Methods

concat()

Combines two or more strings.

const str1 = 'Hello';
const str2 = 'World';
console.log(str1.concat(' ', str2)); // "Hello World"

endsWith()

Checks if a string ends with a specified string/characters.

const str = 'Hello world';
console.log(str.endsWith('world')); // true
console.log(str.endsWith('hello')); // false

includes()

Checks if a string contains a specified string/characters.

const str = 'Hello world';
console.log(str.includes('world')); // true
console.log(str.includes('hello')); // false

indexOf()

Returns the index of the first occurrence of a specified value.

const str = 'Hello world';
console.log(str.indexOf('o')); // 4
console.log(str.indexOf('z')); // -1

isWellFormed()

Checks if a string is well-formed.

const str = 'Hello world';
console.log(str.isWellFormed()); // true

lastIndexOf()

Returns the index of the last occurrence of a specified value.

const str = 'Hello world';
console.log(str.lastIndexOf('o')); // 7
console.log(str.lastIndexOf('z')); // -1

localeCompare()

Compares two strings in the current locale.

const str1 = 'a';
const str2 = 'b';
console.log(str1.localeCompare(str2)); // -1

match()

Matches a string against a regular expression.

const str = 'Hello world';
const regex = /world/;
console.log(str.match(regex)); // ["world"]

matchAll()

Matches a string against a regular expression and returns an iterator.

const str = 'Hello world';
const regex = /o/g;
for (const match of str.matchAll(regex)) {
  console.log(match);
}
// ["o"]
// ["o"]

normalize()

Returns the Unicode Normalization Form of a string.

const str = '\u1E9B\u0323';
console.log(str.normalize('NFC')); // "ẛ̣"

padEnd()

Pads the current string with a specified string to a given length.

const str = 'Hello';
console.log(str.padEnd(10, '!')); // "Hello!!!!!"

padStart()

Pads the current string with a specified string to a given length.

const str = 'Hello';
console.log(str.padStart(10, '!')); // "!!!!!Hello"

repeat()

Returns a new string with a specified number of copies of the string.

const str = 'Hello';
console.log(str.repeat(3)); // "HelloHelloHello"

replace()

Replaces a specified value with another value in a string.

const str = 'Hello world';
console.log(str.replace('world', 'there')); // "Hello there"

replaceAll()

Replaces all occurrences of a specified value with another value in a string.

const str = 'Hello world, world!';
console.log(str.replaceAll('world', 'there')); // "Hello there, there!"

Searches a string for a specified value and returns the position.

const str = 'Hello world';
console.log(str.search('world')); // 6

slice()

Extracts a part of a string and returns a new string.

const str = 'Hello world';
console.log(str.slice(0, 5)); // "Hello"

split()

Splits a string into an array of substrings.

const str = 'Hello world';
console.log(str.split(' ')); // ["Hello", "world"]

startsWith()

Checks if a string starts with a specified string/characters.

const str = 'Hello world';
console.log(str.startsWith('Hello')); // true
console.log(str.startsWith('world')); // false

substring()

Returns the part of the string between the start and end indexes.

const str = 'Hello world';
console.log(str.substring(0, 5)); // "Hello"

toLocaleLowerCase()

Converts a string to lowercase according to the host's locale.

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

toLocaleUpperCase()

Converts a string to uppercase according to the host's locale.

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

toLowerCase()

Converts a string to lowercase.

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

toString()

Returns a string representing the specified object.

const str = 'Hello world';
console.log(str.toString()); // "Hello world"

toUpperCase()

Converts a string to uppercase.

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

toWellFormed()

Ensures the string is well-formed.

const str = 'Hello world';
console.log(str.toWellFormed()); // "Hello world"

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  ';
console.log(str.trimEnd()); // "  Hello world"

trimStart()

Removes whitespace from the beginning of a string.

const str = '  Hello world  ';
console.log(str.trimStart()); // "Hello world  "

valueOf()

Returns the primitive value of a string object.

const str = new String('Hello world');
console.log(str.valueOf()); // "Hello world"

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