Ranges In Loops

You've been using ranges like 1...5 in your loops, but Swift offers more flexibility in how you define these ranges. Let's explore the different range types and a useful technique for counting backwards.

The closed range operator (...) includes both endpoints:

for i in 1...3 {
    print(i)
}
// Output: 1, 2, 3

The half-open range operator (..<) excludes the upper bound, which is especially useful when working with zero-based indices:

for i in 0..<3 {
    print(i)
}
// Output: 0, 1, 2

Sometimes you need to loop in reverse order. The reversed() method lets you iterate backwards through a range:

for i in (1...3).reversed() {
    print(i)
}
// Output: 3, 2, 1

Notice the parentheses around the range—they're required when calling reversed() on a range. This technique is perfect for countdowns or when you need to process items from last to first.