Swift Programming

Conceptual Lesson 1

Arrays: Visual Explainer

Understand how arrays organize related values so you can model data cleanly before writing code.

Swift Programming Xcode iOS

What to focus on while watching

Arrays are ordered collections, so index position matters.
Each element should be the same data type for predictable behavior.
Use arrays when you need to loop, sort, filter, or update related values.

Back to Arrays Module Next: Array Tutorial

Lesson Notes and Walkthrough

An array is an ordered list of values. Think of it like a row of labeled lockers: each locker has a position number, and you can get or change values by position.

Key Ideas for Beginners

Arrays keep related data together in one place.
Order matters because each item has an index.
In Swift, indexes start at 0, not 1.

Basic Example

var colors = ["blue", "green", "red"]
print(colors[0]) // blue
print(colors[2]) // red

How to Read This

colors is the array name.
Each value has a position: 0, 1, 2.
colors[0] means “get the first item.”

Common Beginner Mistakes

Using an index that does not exist (for example colors[5]).
Forgetting indexes start at 0.
Mixing unrelated values in one array, which makes code harder to reason about.

What is an Array?

Conceptual Overview

Programming

Array Programming

Coding Tutorial

Programming

What are Variables?

Series| Part 1

Practice: Array Thinking

~5 min Beginner

Goal: Create an array and inspect elements by index.

Steps

Create an array of three favorite colors.
Read the first and last value by index.
Print a sentence using both values.

Expected Output

First: blue, Last: red

Need a hint?

Index 0 is the first value. Use count - 1 for the last.

Code

import Foundation

var favoriteColors = ["blue", "green", "red"]
let firstColor = favoriteColors[0]
let lastColor = favoriteColors[favoriteColors.count - 1]

print("First: \(firstColor), Last: \(lastColor)")