Swift Data Types

Swift Data Types

Swift has built-in types like Int, Double, Bool and String.

Swift uses type inference to deduce the type from the value.

Basic Types

Declare constants with let and variables with var.

Swift infers the type from the initial value.

let anInt = 42           // Int
let aDouble = 3.14       // Double
let isSwiftFun = true    // Bool
let greeting = "Hello"    // String
print(aDouble)
print(isSwiftFun)
print(greeting)

This example declares common Swift types and prints them.

Type Inference vs Annotation

Swift usually infers the type from the initial value, but you can add a type for clarity.

let inferred = 10          // Int (inferred)
let annotated: Double = 3  // Double (explicit)
print(type(of: inferred), type(of: annotated))

This example contrasts inferred vs. explicit types.