Gets first value.
This is part of package extra-array.
This is browserified, minified version of @extra-array/head.
It is exported as global variable array_head.
CDN: unpkg, jsDelivr.
array.head(x, [vd]);
// x: an array
// vd: default value
const array = require("extra-array");
array.head([1, 2, 3]);
// 1
array.head([], -1);
// -1