Switch Statement Basics

let day = 3
switch day {
case 1:
    print("Monday")
case 2:
    print("Tuesday")
case 3:
    print("Wednesday")
default:
    print("Some other day")
}

let letter: Character = "a"
switch letter {
case "a", "e", "i", "o", "u":
    print("\(letter) is a vowel")
default:
    print("\(letter) is a consonant")
}

let number = 2
switch number {
case 1:
    print("one")
case 2:
    print("two")
case 3:
    print("three")
default:
    print("other")
}

1. Forgetting that Swift's switch must be exhaustive -- every possible value must be handled, often requiring a default case.
2. Expecting implicit fallthrough between cases like in C; Swift cases do NOT fall through automatically unless you write fallthrough explicitly.
3. Using a switch for a simple two-way boolean check where an if-else would be simpler and clearer.

• switch compares a value against multiple case patterns and runs the matching one.
• Swift switches must be exhaustive; a default case covers any remaining values.
• Unlike C, cases do not fall through to the next case automatically.
• Multiple values can be matched in one case using a comma-separated list.