ios - Check if string is 3 chars and 3 number in Swift

Question

I'm trying to create a function that validate my string if it is using this format

ABC123
First three characters should be letters and the other 3 should be numbers

I have no idea on how to start

Thanks

Answer 1

您可以使用字符串上的正则表达式匹配来做到这一点，如下所示：

    let str = "ABC123"
    let optRange = str.rangeOfString("^[A-Za-z]{3}\\d{3}$", options: .RegularExpressionSearch)
    if let range = optRange {   
        println("Matched")
    } else {
        println("Not matched")
    }

上面的正则表达式要求匹配占据整个字符串（两端的^和锚点），包含三个字母和三个数字。$[A-Za-z]{3}\\d{3}

如果您愿意，也可以将其用作扩展：

    extension String {
        var match: Bool {
            return rangeOfString("^[A-Za-z]{3}\\d{3}$", options: .RegularExpressionSearch) != nil
        }
    }


    "ABC123".match // true