如何在Swift游乐场玩STDIN

I know that to program in STDIN and STDOUT, we need to make an command line project in Xcode. But how do I take a standard input in playground.

我知道要在STDIN和STDOUT中编程,我们需要在Xcode中创建一个命令行项目。但是如何在操场上进行标准输入。

Whenever I try to run such code in playground

每当我尝试在操场上运行这样的代码时

var input = readLine()!

I always get this error

我总是得到这个错误

Execution was interrupted, reason: EXC_BAD_INSTRUCTION (Code=EXC_l386_INVOP, subcode=0x0)

执行被中断,原因:EXC_BAD_INSTRUCTION(代码= EXC_l386_INVOP,子代码= 0x0)

Is it possible to take STDIN in playground or not?

是否可以在操场上带STDIN?

UPDATE

I know this error is because of nil input variable but want to know how to overcome this nil value.

我知道这个错误是因为nil输入变量但是想知道如何克服这个nil值。

5 个解决方案

#1

Fixed Solution for SWIFT 3

SWIFT 3的固定解决方案

To make it work, Create a new command line tool project.

要使其工作,请创建一个新的命令行工具项目。

Go to "File" -> "New" -> "Project" -> "macOS" -> "Command Line Tool".

转到“文件” - >“新建” - >“项目” - >“macOS” - >“命令行工具”。

import Foundation

print("Hello, World!")


func solveMefirst(firstNo: Int , secondNo: Int) -> Int {
    return firstNo + secondNo
}

func input() -> String {
    let keyboard = FileHandle.standardInput
    let inputData = keyboard.availableData
    return NSString(data: inputData, encoding:String.Encoding.utf8.rawValue) as! String
}

let num1 = readLine()
let num2 = readLine()

var IntNum1 = Int(num1!)
var IntNum2 = Int(num2!)

print("Addition of numbers is :  \(solveMefirst(firstNo: IntNum1!, secondNo: IntNum2!))")

And run the project using CMD + R

并使用CMD + R运行项目

#2

Try using Optional Chaining:

尝试使用可选链接:

if let input = readLine() {
    print("Input: \(input)")
} else {
    print("No input.")
}

#3

Playground can not read an input from the commend line.

游乐场无法从推荐线读取输入。

You can use a custom "readLine()" function and a global input variable, each element in the input array is presenting a line:

您可以使用自定义“readLine()”函数和全局输入变量,输入数组中的每个元素都会显示一行:

import Foundation

var currentLine = 0
let input = ["5", "5 6 3"]

func readLine() -> String? {
    if currentLine < input.endIndex {
        let line = input[currentLine]
        currentLine += 1
        return line
    } else {
        return nil
    }
}

let firstLine = readLine() //  5
let secondLine = readLine() // 5 6 3
let thirdLine = readLine() // nil

#4

For getting input from command line, like Console.ReadLine... Chalkers has a solution as follows.

要从命令行获取输入,例如Console.ReadLine ... Chalkers有如下解决方案。

func input() -> String {
    var keyboard = NSFileHandle.fileHandleWithStandardInput()
    var inputData = keyboard.availableData
    return NSString(data: inputData, encoding:NSUTF8StringEncoding) as! String
}

please ask for further if it doesn't work Vinod.

如果它不起作用,请进一步询问Vinod。

#5

-1

Go to

New > Project > MacOs > Command Line Tool

新建>项目> MacOs>命令行工具

then you can apply :

然后你可以申请:

let value1: String?

让value1:String?

value1 = readLine()
print(value ?? "")

"" for the default value

“”表示默认值

#1