Bool type and logical operators in Swift

Introduction

The Bool type helps us represent true or false values. Logical operators let us combine or change these true/false values to make decisions in code.

Checking if a light is on or off in a smart home app.

Deciding if a user is logged in before showing their profile.

Determining if a number is positive and even before processing it.

Checking multiple conditions like if a door is locked and the alarm is set.

Syntax

Swift

let isTrue: Bool = true
let isFalse: Bool = false

// Logical operators
let andResult = true && false  // AND
let orResult = true || false   // OR
let notResult = !true          // NOT

Bool values are either true or false.

Logical operators combine Bool values to make new Bool values.

Examples

AND (&&) returns true only if both a and b are true.

Swift

let a = true
let b = false
let result = a && b

OR (||) returns true if either a or b is true.

Swift

let a = true
let b = false
let result = a || b

NOT (!) flips the value: true becomes false, false becomes true.

Swift

let a = true
let result = !a

Sample Program

This program checks if it is raining and if you have an umbrella. It uses AND (&&) and NOT (!) to decide what message to print.

Swift

import Foundation

let isRaining = true
let haveUmbrella = false

if isRaining && haveUmbrella {
    print("You can go outside safely.")
} else if isRaining && !haveUmbrella {
    print("Better stay inside or get wet.")
} else {
    print("Enjoy your day outside!")
}

Important Notes

Use parentheses to group conditions for clarity, like (a && b) || c.

Logical operators only work with Bool values, not numbers or strings.

Summary

Bool type stores true or false values.

Use && for AND, || for OR, and ! for NOT operations.

Logical operators help make decisions by combining true/false values.