The Array.from()
method creates a new shallow-copied Array instance from an array-like or iterable object.
This can be really useful when you want to convert a Map
or Set
to an Array
, or as an alternative way to turn a string
into an Array
(e.g. instead of using something like "MyString".split("")
)
// array-like object
console.log(Array.from('hello')); // ["h","e","l","l","o"]
// using an optional mapper function
console.log(Array.from([1,2,3], x => x * 10)); // [10,20,30]
// iterable objects (Map & Set)
console.log(Array.from(new Set([1,2,3]))); // [1,2,3]
console.log(Array.from(new Map([[1,1.1],[2,2.2],[3,3.3]]))); // [[1,1.1],[2,2.2],[3,3.3]]