swift - 错误 : '...' is not a prefix unary operator

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，因此非常感谢任何相关链接或任何类型的帮助。使用 swift 4

Answer 1

正如 Martin 和其他人所说，这在 Swift 4 中有效。在早期版本中，您可能想使用它:

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