How can I write a simple JScript input/output program?

I'm planning on using JavaScript to enter an informatics competition (BIO) tomorrow. However, I can't rely on the examiner having a browser with a decent JavaScript engine, so I was hoping to use Microsoft's JScript instead.

However, the documentation is, quite frankly, crap. Can someone post some example code that reads in a line of text, calls foo(string) on it, and echos the output to the command line?

Similarly, how do I actually run it? 开发者_如何学PythonWill wscript.exe PATH_TO_JS_FILE do the trick?

If you're using the command-line, I'd execute the script using CSCRIPT.EXE. ie: CSCRIPT.EXE myscript.js This is because WScript.Echo from WSCRIPT will create a dialog box and from CSCRIPT outputs a line to the console. Run this in a command window (CMD).

Reading a line from console into variable:

var x = WScript.StdIn.ReadLine();

Where StdIn is a TextStream object. There is also an StdOut which can be used in place of WScript.Echo()...

Writing the output of foo(x) to console: (must run under CSCRIPT)

WScript.Echo(foo(x));

You can use the WScript object to determine which engine you are running under, there's a question/answer for that (VBScript, but uses the same objects under JScript) here.

If you want to be sure your program only runs in the command line, you may use the WScript.StdIn and WScript.StdOut objects/properties:

var myString = WScript.StdIn.ReadLine();
WScript.StdOut.WriteLine(myString);

and run it with cscript.exe. But if you want it to be a GUI program, it is a bit more difficult considering that JScript doesn't have a native InputBox function like VBScript. However, as described here we may use Windows Script Host (WSH). Create a .wsf file:

<?xml version="1.0" encoding="ISO-8859-1"?>
<job id="testJScriptInputBox">
    <script language="VBScript">
    <![CDATA[
        Function WSHInputBox(Message, Title, Value)
            WSHInputBox = InputBox(Message, Title, Value)
        End Function
    ]]>
    </script>

    <script language="JScript">
    <![CDATA[
        var vbOKOnly = 0;                // Constants for Popup
        var vbInformation = 64;

        var title = "InputBox function for JScript";
        var prompt = "Enter a string: ";

        var WshShell = WScript.CreateObject("WScript.Shell");

        var result = WSHInputBox(prompt, title, "New York");

        if (result != null)   
        {  // Cancel wasn't clicked, so get input.
            var intDoIt =  WshShell.Popup(result,
                                          0,
                                          "Result",
                                          vbOKOnly + vbInformation);
        }
        else
        { // Cancel button was clicked.
            var intDoIt =  WshShell.Popup("Sorry, no input",
                                          0,
                                          "Result",
                                          vbOKOnly + vbInformation);
        }                           

    ]]>
    </script>
</job>

and run it with either cscript.exe or wscript.exe. Alternatively, you could also use HTML Application (HTA) to create more elaborate GUIs.