keys

Lists all indices. 🏃 📼 📦 🌔 📒

Similar: keys, values, entries.

array.keys(x);
// x: an array

const array = require('extra-array');

var x = [1, 2, 3];
[...array.keys(x)];
// [ 0, 1, 2 ]

References

• Array.prototype.keys: MDN web docs