Return Values

So far, our functions have performed actions like printing messages. But often you need a function to calculate something and give back a result. This is where return values come in.

To make a function return a value, add an arrow (->) followed by the return type after the parentheses, then use the return keyword:

func add(a: Int, b: Int) -> Int {
    return a + b
}

let sum = add(a: 3, b: 5)
print(sum)  // Output: 8

The -> Int tells Swift this function returns an integer. The return statement sends the value back to wherever the function was called. You can then store that value in a variable, use it in calculations, or pass it to another function.

func multiply(x: Int, y: Int) -> Int {
    return x * y
}

let result = multiply(x: 4, y: 3) + 10
print(result)  // Output: 22

Functions can return any type—String, Double, Bool, and more. The return type must match what you actually return:

func isEven(number: Int) -> Bool {
    return number % 2 == 0
}

print(isEven(number: 4))  // Output: true