Subscripts with Swift arrays

The following example shows how to use subscripts to access and change the values of an array:

var arrayOne = [1, 2, 3, 4, 5, 6]
print(arrayOne[3])  //Displays '4'
arrayOne[3] = 10
print(arrayOne[3])  //Displays '10'

In the preceding example, we create an array of integers and then use the subscript syntax to display and change the element at index three. Subscripts are mainly used to set or retrieve information from a collection. We generally do not use subscripts when specific logic needs to be applied to determine which item to select. As an example, we would not want to use subscripts to append an item to the end of the array or to retrieve the number of items in the array. To append an item to the end of an array, or to get the number of items in an array, we use functions or properties, such as the following:

arrayOne.append(7)  //append 7 to the end of the array
arrayOne.count  //returns the number of items in an...