JavaScript String Methods Cheatsheet

Here's a cheatsheet of the latest ECMAScript string methods in Markdown format:

• String.prototype.at(index: number) Will get character at certain index in a string.

  'hello'.at(0) 

Results: 'h'

• String.prototype.charAt(index: number) Returns the character at a specified index (position) in a string.

  'hello'.charAt(0) 

Results: 'h'

• String.prototype.charCodeAt(index: number) Returns the code of the character at a specified index in a string.

  'hello'.charCodeAt(0) 

Results: 72 (The Unicode of 'H')

• String.prototype.padStart(targetLength: number, padString: string) Pads another string (multiple times) until the resulting string reaches the given length.

  '5'.padStart(4, '0') 

Results: '005'

• String.prototype.padEnd(targetLength: number, padString: string) Pads another string (multiple times) until it reaches a given length.

  '5'.padEnd(4, '0') 

Results: '5000'

• String.prototype.repeat(count: number) Returns a new string with a specified number of copies of the string it was called on.

  'hello'.repeat(2) 

Results: 'hellohello'

• String.prototype.trim() Removes whitespace from both sides of a string.

  '   Hello World   '.trim() 

Results: 'Hello World'

• String.prototype.trimStart() Removes whitespace only from the start of a string.

  '   Hello World   '.trimStart() 

Results: 'Hello World '

• String.prototype.trimEnd() Removes whitespace only from the end of a string.

  '   Hello World   '.trimEnd() 

Results: ' Hello World'

• String.prototype.replace(searchValue: string | RegExp, replacement: string | (substring: string, ...args: any[]) => string) Searches a string for a specified value, or a regular expression, and returns a new string where the specified values are replaced.

  'Hello World'.replace('World', 'there') 

Results: 'Hello there'

• String.prototype.match(regexp: RegExp) Searches a string for a match against a regular expression, and returns the matches.

  'The rain in SPAIN stays mainly in the plain'.match(/ain/gi) 

Results: ['ain', 'AIN', 'ain', 'ain']

• String.prototype.search(regexp: RegExp) Searches a string for a specified value, or regular expression, and returns the position of the match.

  'Hello World'.search('World') 

Results: 6

• String.prototype.slice(start?: number, end?: number) Extracts a part of a string and returns the extracted part in a new string.

  'Apple, Banana, Kiwi'.slice(7, 13) 

Results: 'Banana'

• String.prototype.split(separator?: string | RegExp, limit?: number) Splits a string into an array of substrings.

  'How are you doing today?'.split(' ') 

Results: ['How', 'are', 'you', 'doing', 'today?']