Is there no input() function in Swift? No. Not for now. But how then can we enter a number or a string from the command line interface (CLI)?<\/p>\n
1. Copy this function to your code:<\/p>\n
func input() -> String {\r\n\u00a0\u00a0 \u00a0var keyboard = NSFileHandle.fileHandleWithStandardInput()\r\n\u00a0\u00a0 \u00a0var inputData = keyboard.availableData\r\n\u00a0\u00a0 \u00a0var strData = NSString(data: inputData, encoding: NSUTF8StringEncoding)!\r\n\u00a0\u00a0 \u00a0return strData.stringByTrimmingCharactersInSet(NSCharacterSet.newlineCharacterSet())\r\n}<\/pre>\n2. Use it like so:<\/p>\n
print(\"Enter number: \")\r\nlet n_str = input() \/\/ NOTE: n_str is an Optional (type), this means String or nothing\r\nlet n = n_str.toInt()! \/\/ NOTE: ! \"unpacks\" the Optional type n_str<\/pre>\n <\/p>\n
3. Testing: What happens, if I enter a Number:<\/p>\n
Enter number: 12<\/strong><\/pre>\nResult: Just seems to work<\/p>\n
<\/p>\n
4. Testing: What happens if I just enter ENTER:<\/p>\n
Enter number:\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \/\/ <--- I just hit ENTER<\/strong> here<\/pre>\nfatal error: unexpectedly found nil while unwrapping an Optional value\r\n0\u00a0 swift\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0x00000001039d82b8 llvm::sys::PrintStackTrace(__sFILE*) + 40\r\n1\u00a0 swift\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0x00000001039d8794 SignalHandler(int) + 452\r\n[...]\r\n<\/pre>\nResult: It crashes, which is better then continue with undefined values<\/p>\n
5. Testing: What happens if I just enter a string not a number:<\/p>\n
Enter Number: abc<\/strong><\/pre>\nfatal error: unexpectedly found nil while unwrapping an Optional value\r\n0\u00a0 swift\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0x000000010bc512b8 llvm::sys::PrintStackTrace(__sFILE*) + 40\r\n1\u00a0 swift\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0x000000010bc51794 SignalHandler(int) + 452\r\n[...]<\/pre>\nResult: It does crash, witch is better then continue with undefined values!<\/p>\n
6. Conclusion<\/p>\n
So, sometimes it's a better your program crashes then just go ahead somehow undefined as it's possible with plain C for example.<\/p>\n
Missing Swift Computer Language Feature: But really, Swift should and has to include an input() function by default. Apple, if you read this, just do it \ud83d\ude09 Swift seems to be a great new computer language and I start to really like it.<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Is there no input() function in Swift? No. Not for now. But how then can we enter a number or a string from the command line interface (CLI)? 1. Copy this function to your code: func input() -> String { \u00a0\u00a0 \u00a0var keyboard = NSFileHandle.fileHandleWithStandardInput() \u00a0\u00a0 \u00a0var inputData = keyboard.availableData \u00a0\u00a0 \u00a0var strData = NSString(data: …<\/p>\n