unshift$ - nodef/extra-array GitHub Wiki

Add values to the start!

Alternatives: unshift, unshift$. Similar: push, pop, shift, unshift.

function unshift$(x, ...vs)
// x:  an array (updated!)
// vs: values to add

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

var x = [3, 4];
xarray.unshift$(x, 2);
// → [ 2, 3, 4 ]

x;
// → [ 2, 3, 4 ]

var x = [3, 4];
xarray.unshift$(x, 1, 2);
// → [ 1, 2, 3, 4 ]

References

• Array.unshift() : MDN Web Docs
• array_unshift() : PHP
• Array.unshift() : Ruby
• immutable-iterable-prototype : @azu