Exploring range operators

Imagine you need to write a program for a department store that automatically sends a discount voucher to customers between the ages of 18 and 30. It would be very cumbersome if you needed to set up an if or switch statement for each age. It would be much more convenient if there was a way to specify a range of numbers, and that is what a range operator does.

Important information

For more information on range operators, visit https://docs.swift.org/swift-book/LanguageGuide/BasicOperators.html.

Let's say you want to represent a sequence of numbers from 10 to 20. You don't need to specify every value; you can just specify the first number and the last number in this way:

firstNumber...lastNumber

Let's try this out in the playground. Follow these steps:

1. Add the following code to your playground and click the Play/Stop button to run it:

   let myRange = 10...20

2. This will assign a number sequence that starts with 10 and ends...