JavaScript Array to Set

Thomas picture Thomas · Mar 10, 2015 · Viewed 139.6k times · Source

MSDN references JavaScript's Set collection abstraction. I've got an array of objects that I'd like to convert to a set so that I am able to remove (.delete()) various elements by name:

var array = [
    {name: "malcom", dogType: "four-legged"},
    {name: "peabody", dogType: "three-legged"},
    {name: "pablo", dogType: "two-legged"}
];

How do I convert this array to a set? More specifically, is it possible to do this without iterating over the above array? The documentation is relatively lacking (sufficient for instantiated sets; not for conversions - if possible).

I may also be thinking of the conversion to a Map, for removal by key. What I am trying to accomplish is an iterable collection that can be accessed or modified via accessing the elements primarily via a key (as opposed to index).

Conversion from an array to the other being the ultimate goal.

Answer

levi picture levi · Mar 10, 2015

Just pass the array to the Set constructor. The Set constructor accepts an iterable parameter. The Array object implements the iterable protocol, so its a valid parameter.

var arr = [55, 44, 65];
var set = new Set(arr);
console.log(set.size === arr.length);
console.log(set.has(65));

See here