Loops & Playing sound in Swift

What I learned today:

• Basics – Loops.
• Each button in Xcode has a tag.
• Basics – Do/Catch Statement.
• Playing sound in Swift.
• Global & Local Scope

Loops

// Will print numbers in a loop

for number in 1...100 {

print(number)

}


// Starts from reverse

for number in (1...100).reversed {

print(number)

}

Buttons – Tags

Each button in Xcode has a tag. We can use sender.tag to get information regarding which button was pressed.

// Print to the console which button was pressed

print(sender.tag)

// Perform different tasks as per different button pressed 

if sender.tag == 1 {
print("You pressed button one.")
} else if sender.tag == 2 {
print("You pressed button two.")
} else {
print("You pressed the other button.")
}

• Extra : If you need to know anything about a function which you don’t understand in Xcode, you can hold alt key in Mac and click on that function and Xcode will display it’s details.

Global & Local Scope

• If a variable is declared inside a function then it is considered to have local scope, which means it cannot be used outside that function.
• Global scope – the variable is declared normally outside any function and can be detected by Xcode and used throughout the code.

Do/Catch Statement

// Try to do something. If not possible then throw an error.

do {
try
} catch {
print(error)
}

Playing sound in Swift

// Firstly we need to import AudioToolBox

import AudioToolbox

// nameofsoundfile refers to the filname, extension can be .wav, .mp3 etc

if let soundURL = Bundle.main.url(forResource: "nameofsoundfile", withExtension: "wav") {
            
            var mySound: SystemSoundID = 0
            AudioServicesCreateSystemSoundID(soundURL as CFURL, &mySound)
            // Play
            AudioServicesPlaySystemSound(mySound);