obj-c to Swift convert code - objective-c

Question

So I'm trying to convert some obj-c code into swift but I'm stuck on a part of it.
How can I do something like this in swift?
- (void)sometMethod:(NSString *)s {
NSString * crlfString = [s stringByAppendingString:#"\r\n"];
uint8_t *buf = (uint8_t *)[crlfString UTF8String];}
The real problem is this line
uint8_t *buf = (uint8_t *)[crlfString UTF8String];

Answer 1

What do you want to do with the UTF-8 buffer? Generally, it is more convenient to convert the string directly to an NSData object. But you can also translate your Obj-C code one by one to Swift. Here are both variants:
import Foundation
func appendCRLFAndConvertToUTF8_1(s: String) -> NSData {
let crlfString: NSString = s.stringByAppendingString("\r\n")
let buffer = crlfString.UTF8String
let bufferLength = crlfString.lengthOfBytesUsingEncoding(NSUTF8StringEncoding)
let data = NSData(bytes: buffer, length: bufferLength)
return data;
}
func appendCRLFAndConvertToUTF8_2(s: String) -> NSData {
let crlfString = s + "\r\n"
return crlfString.dataUsingEncoding(NSUTF8StringEncoding)!
}
let s = "Hello 😄"
let data1 = appendCRLFAndConvertToUTF8_1(s)
data1.description
let data2 = appendCRLFAndConvertToUTF8_2(s)
data2.description
data1 == data2
And if you want to iterate over the UTF-8 code units and not deal with a buffer, use something like:
for codeUnit in String.utf8 {
println(codeUnit)
}