md5 hash returns with encapsulation in swift

Question

I have used this md5 and I get the hashed result. However, the return is like this: <8f833933 03a151ea 33bf6e3e bbc28594>. Am new to swift so am not entirely sure whether it's an encapsulation. How do I get rid of the less and greater than sign?

Answer 1

As you can see from the signature, the function returns a NSData object:

func md5(#string: String) -> NSData

If you want to convert it to a string, you’ll need to encode it in a human-readable format. The most common is a hexadecimal representation.

If you use the newer Swift 2 function from that question, which returns a UInt8 array

func md5(string string: String) -> [UInt8] {
    var digest = [UInt8](count: Int(CC_MD5_DIGEST_LENGTH), repeatedValue: 0)
    if let data = string.dataUsingEncoding(NSUTF8StringEncoding) {
        CC_MD5(data.bytes, CC_LONG(data.length), &digest)
    }

    return digest
}

you could use this handy toHex function:

func toHex(bytes: [UInt8]) -> String {
    var numbers = [String]()
    for byte in bytes {
        if byte < 0x10 {
            numbers.append("0")
        }
        numbers.append(String(byte, radix: 16, uppercase: true))
    }
    return numbers.joinWithSeparator("")
}

Then this returns a string:

toHex(md5("Hello"))

(In my opinion you should always prefer pure Swift types (array of UInt8) over Foundation types (NSData).)