keys

List all keys.

Similar: randomKey, keys, has.

function keys(x)
// x: entries

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

var x = [["a", 1], ["b", 2], ["c", 3]];
[...entries.keys(x)];
// → [ "a", "b", "c" ]

References

• Array.prototype.values: MDN web docs