size

Find the size of a map.

Similar: size, isEmpty.

function size(x)
// x: a map

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

var x = new Map([['a', 1], ['b', 2], ['c', 3]]);
map.size(x);
// → 3

References

• Array.prototype.slice: MDN web docs
• Array.length: MDN web docs