Swift

【Swift】配列を回して全ての要素にアクセスする

for-in

配列を普通に回す場合は「for-in」を使います

let languages: [String] = ["Swift", "Java", "Ruby", "Javascript", "PHP"]
for language in languages {
    print(language)
}
//Swift
//Java
//Ruby
//Javascript
//PHP

配列を反対に回したい場合は「reversed()」を使います

let languages: [String] = ["Swift", "Java", "Ruby", "Javascript", "PHP"]
for language in languages.reversed() {
    print(language)
}
//PHP
//Javascript
//Ruby
//Java
//Swift

forEach(_:)

「forEach(_:)」は基本的には普通のfor文とやっていることは変わりません

let languages: [String] = ["Swift", "Java", "Ruby", "Javascript", "PHP"]
languages.forEach {
    print($0)
}
//Swift
//Java
//Ruby
//Javascript
//PHP

enumrated()

「enumrated()」では配列を回すのと同時にゼロから始まる連続した数字を返します

for (n, language) in languages.enumerated() {
    print("\(n): \(language)")
}
//0: Swift
//1: Java
//2: Ruby
//3: Javascript
//4: PHP