Mastering Switch/Case Statements

Switch/Case statements provide a clean and concise way to handle multiple conditions and are often used in place of long chains of if/else statements.

Basic Switch/Case Syntax

The basic structure of a Switch/Case statement in Swift looks like this:

switch expression {
case value1:
    // Code block executed when expression matches value1
case value2:
    // Code block executed when expression matches value2
// Add more cases as needed...
default:
    // Code block executed when none of the cases match the expression
}

Matching on Constants

You can use a variety of data types as the expression, including integers, characters, strings, and enumerations. For instance, to match on constants:

let dayOfWeek = 3

switch dayOfWeek {
case 1:
    print("Sunday")
case 2:
    print("Monday")
case 3:
    print("Tuesday")
// Add more cases for other days...
default:
    print("Invalid day")
}

Matching on Ranges

Switch/Case statements are not limited to matching single values; they can also match ranges of values:

let score = 85

switch score {
case 0..<60:
    print("You failed.")
case 60..<70:
    print("You passed with a D.")
case 70..<80:
    print("You passed with a C.")
case 80..<90:
    print("You passed with a B.")
case 90...100:
    print("Congratulations! You got an A!")
default:
    print("Invalid score.")
}

Pattern Matching with Tuples

Tuples enable you to perform more complex pattern matching:

let point = (2, 2)

switch point {
case (0, 0):
    print("Origin")
case (_, 0):
    print("On the x-axis")
case (0, _):
    print("On the y-axis")
default:
    print("Somewhere in 2D space")
}

Where Clauses

You can use where clauses to add additional conditions to your cases:

let age = 18
let isStudent = true

switch age {
case 0..<18:
    print("You are a minor.")
case 18..<65 where isStudent == false:
    print("You are an adult.")
case 18..<65 where isStudent == true:
    print("You are an adult student.")
default:
    print("You are a senior citizen.")
}