Range Operators

Hello,

In this lesson, we will learn about the range operators provided to us by Swift. 

The first thing we will learn is the Closed Range Operator. This operator creates a closed range, including numbers defined by it.

Let's take a look at our example.

for index in 1...5 {
    print("\(index) times 5 is \(index * 5)")
}
// 1 times 5 is 5
// 2 times 5 is 10
// 3 times 5 is 15
// 4 times 5 is 20
// 5 times 5 is 25

The Half-Open Range operator creates a half-open range, as we can understand from its name.

When we look at the example below carefully, although the length of the array is 4, the range is between 0 and 3.

let cats = ["Lucy", "Garfield", "Tom", "Sylvester"]
let count = cats.count
for i in 0..<count {
    print("Cat \(i + 1) is called \(cats[i])")
}
// Person 1 is called Anna
// Person 2 is called Alex
// Person 3 is called Brian
// Person 4 is called Jack

One-Sided Ranges

The last operator we will learn is the One-sided range. By using this operator, we can produce a sequence as much as we want by choosing a starting point, provided that we move in one direction.

The sentence was a little confusing, right?

Let's learn how to use this operator by giving an example.

let names = ["Leo", "Lucy", "Garfield", "Tom"]
for name in names[2...] {
    print(name)
}
// Brian
// Jack

for name in names[...2] {
    print(name)
}
// Anna
// Alex
// Brian

Congratulations 🎉

In this section, we learned the concept of Range operator that we will use frequently in our codes.

See you in the next lesson 💯