DEV Community

Cover image for JavaScript Array Methods reference
Chandra Dasari
Chandra Dasari

Posted on • Updated on

JavaScript Array Methods reference

There are a ton of array methods that JavaScript provides. Here is a reference to some useful ones in different categories

To add/remove elements:

  • push(...items) – adds items to the end of the array
  • pop() – extracts an item from the end of the array
  • shift() – extracts an item from the beginning of the array
  • unshift(...items) – adds items to the beginning
  • slice(start, end) – creates a new array, copies elements from position start till end (not inclusive) into it.
  • concat(...items) – returns a new array: copies all members of the current one and adds items to it. If any of items is an array, then its elements are taken.

To transform an array

  • map(func) - creates a new array from results of calling func for every element.
  • sort(func) - sorts the array in-place, then returns it.
  • reverse() - reverses the array in-place, then returns it.
  • split/join - convert a string to array and back.
  • reduce(func, initial) - calculate a single value over the array by calling func for each element and passing an intermediate result between the calls.

To search in an array

  • indexOf/lastIndexOf(item, pos) - look for item starting from position pos, return the index or -1 if not found.
  • includes(value) - returns true if the array has value, otherwise false.
  • find/filter(func) - filter elements through the function, return first/all values that make it return true.
  • findIndex - is like find but returns the index instead of a value.

Iterating in an array

  • forEach(func) -- calls func for every element.

For a more detailed reference about arrays and array methods check out MDN

Top comments (0)