Void addAt(var [a] array, a elem, Int idx)
Arguments
array: The array to act onelem: The new elementidx: The index of the element to add before
Usage
Add (in-place) an element before position idx.
array = [1,2,3,4,5,6,7];
addAt(array,5,2);
// array = [1,2,5,3,4,5,6,7];