14.5 Appending Items to an Array
Items may be added to an array using either the append method or + and += operators. The following, for example, are all valid techniques for appending items to an array:
treeArray.append("Redwood")
treeArray += ["Redwood"]
treeArray += ["Redwood", "Maple", "Birch"]
14.5.1 Inserting and Deleting Array Items
New items may be inserted into an array by specifying the index location of the new item in a call to the array’s insert(at:) method. An insertion preserves all existing elements in the array, essentially moving them to the right to accommodate the newly inserted item:
treeArray.insert("Maple", at: 0)
Similarly, an item at a specific array index position may be removed using the remove(at:) method call:
treeArray.remove(at: 2)
To remove the last item in an array, simply make a call to the array’s removeLast method as follows:
treeArray.removeLast...