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