Range operators (... and ..<) in Swift - Mini Project: Build & Apply

Using Range Operators (... and ..<) in Swift

📖 Scenario: You are organizing a small library and want to list books by their shelf numbers. You will use Swift's range operators to select shelves.

🎯 Goal: Learn how to use the closed range operator ... and the half-open range operator .. to select ranges of shelf numbers.

📋 What You'll Learn

Create an array called shelves with shelf numbers from 1 to 10

Create a variable called closedRange using the closed range operator ... to select shelves 3 to 7

Create a variable called halfOpenRange using the half-open range operator ..< to select shelves 3 to 7 (excluding 7)

Print the selected shelves for both ranges

💡 Why This Matters

🌍 Real World

Range operators help select parts of lists or sequences, like choosing shelves in a library or pages in a book.

💼 Career

Understanding range operators is useful for filtering data, looping through parts of collections, and writing clear, concise code in Swift.

1

Create the shelves array

Create an array called shelves with the numbers from 1 to 10.

Swift

# Create the shelves array with numbers 1 to 10
# Your code here

Need a hint?

Use Array(1...10) to create an array with numbers from 1 to 10.

2

Create the closed range variable

Create a variable called closedRange using the closed range operator ... to select shelves from 3 to 7.

Swift

let shelves = Array(1...10)
# Create closedRange using shelves and the closed range operator ...
# Your code here

Need a hint?

Use shelves[2...6] to select shelves from index 2 to 6 inclusive.

3

Create the half-open range variable

Create a variable called halfOpenRange using the half-open range operator ..< to select shelves from 3 to 7, excluding 7.

Swift

let shelves = Array(1...10)
let closedRange = shelves[2...6]
# Create halfOpenRange using shelves and the half-open range operator ..<
# Your code here

Need a hint?

Use shelves[2..<6] to select shelves from index 2 up to but not including 6.

4

Print the selected shelves

Print the variables closedRange and halfOpenRange to show the selected shelves.

Swift

let shelves = Array(1...10)
let closedRange = shelves[2...6]
let halfOpenRange = shelves[2..<6]
# Print closedRange and halfOpenRange
# Your code here

Need a hint?

Use print() with string interpolation to show the arrays.