Swift筆記：Control Flow

原本在Objective-C中的for (a  in  Array)的小括號可以省略，變成

let individualScores = [75, 43, 103, 87, 12]
var teamScore = 0
for score in individualScores {
    if score > 50 {
        teamScore += 3
    } else {
        teamScore += 1
    }
}

在if裏面，判斷式必須要是布林表示，所以 if a{....}這樣的方式會錯誤，a不會自動和0做比較。

for...in也可以用在dictionary上，例如

let interestingNumbers = [
    "Prime": [2, 3, 5, 7, 11, 13],
    "Fibonacci": [1, 1, 2, 3, 5, 8],
    "Square": [1, 4, 9, 16, 25],
]
var largest = 0
for (kind, numbers) in interestingNumbers {
    for number in numbers {
        if number > largest {
            largest = number
        }
    }
}

可以用...來表示範圍，例如

var firstForLoop = 0
for i in 0..3 {
    firstForLoop += i
}