错误：＆＃39; ...＆＃39;不是前缀一元运算符

Question

代码：

let names = ["Anna", "Alex", "Brian", "Jack"]
for name in names[...2] {
    print(name)
}

错误：

Playground execution failed: error: MyPlayground.playground:3:19: error: '...' is not a prefix unary operator
for name in names[...2] {

我是swift的新手，因此任何相关链接或任何形式的帮助都将受到高度赞赏。使用swift 4

Answer 1

正如Martin和其他人所说，这在Swift 4中是有效的。在早期版本中，你可能想要使用它：

let names = ["Anna", "Alex", "Brian", "Jack"]
for name in names[0..<3] {
    print(name)
}