Swift 2.2 遍历字符串并获取字符和索引

Swift 2.2 loop through string and get char & index

我正在尝试循环遍历 String 获取字符及其索引。听起来很简单..但我没有找到正确的语法。

这是我正在尝试的:

let str = "testString"
for (index, char) in str.characters  {
    print(index)
    print(char)
}

for (index, char) in enumerate(str.characters)  {...}
let str = "testString"
for (index, element) in str.characters.enumerate() {
    print(index)
    print(element)
}

Swift 4

let str = "Swift 4"
for (index, element) in str.enumerated() {
    print(index)
    print(element)
}