Swift, Apple's powerful programming language, offers a rich set of data types to represent various kinds of values. Understanding these types is crucial for effective Swift development.

Basic Data Types

Integers

Integers are whole numbers without fractional components. Swift provides signed and unsigned integers of various sizes.

let age: Int = 30
let unsignedValue: UInt = 42

Floating-Point Numbers

For decimal numbers, Swift offers two floating-point types: Double (64-bit) and Float (32-bit).

let pi: Double = 3.14159
let height: Float = 1.75

Booleans

Booleans represent true or false values, essential for conditional logic.

let isSwiftAwesome: Bool = true

Strings

Strings are sequences of characters, used for text representation.

let greeting: String = "Hello, Swift!"

Complex Data Types

Arrays

Arrays store ordered collections of values of the same type. Learn more about Swift Arrays.

let fruits: [String] = ["Apple", "Banana", "Orange"]

Sets

Sets are unordered collections of unique values. Explore Swift Sets for more details.

let uniqueNumbers: Set = [1, 2, 3, 4, 5]

Dictionaries

Dictionaries store key-value pairs. Dive deeper into Swift Dictionaries.

let capitals: [String: String] = ["France": "Paris", "Japan": "Tokyo"]

Type Safety and Inference

Swift is a type-safe language, meaning it helps you be clear about the types of values your code can work with. It also features powerful Type Inference, often allowing you to omit explicit type annotations.

Type Annotations

You can explicitly declare a variable's type using type annotations:

var score: Int = 0

Type Inference

Swift can often infer the type based on the initial value:

var name = "Alice" // Swift infers this as String

Optionals

Optionals are a powerful feature in Swift, allowing you to represent the absence of a value. They add a layer of safety to your code by forcing you to handle potential nil values explicitly.

var optionalName: String? = nil
optionalName = "Bob"

Best Practices

Choose the appropriate data type for your values to ensure efficiency and clarity.
Use type inference when possible to make your code more concise.
Leverage optionals to handle potentially absent values safely.
Consider using more specific number types (like Int8 or Float) when you need to optimize memory usage.

Understanding Swift data types is fundamental to writing efficient and error-free code. As you progress, explore more advanced topics like Enumerations and Structures to further enhance your Swift programming skills.