Returns a copy of this array.
This is a 'shallow' copy of the array. That means that the elements are not individually cloned, and instead they are now present in both the original and new array.
ns = [ 1, 2, 3 ]
ns2 = ns.clone()
ns2[0] = 400
console( ns ) // prints [ 1, 2, 3 ]
console( ns2 ) // prints [ 400, 2, 3 ]