throw Statement (Windows Scripting - JScript)

Generates an error condition that can be handled by a try...catch...finally statement.

Syntax

throw exception 

Remarks

The required exception argument can be any expression.

The following example throws an error based on a passed-in value, and then illustrates how that error is handled in a hierarchy of try...catch statements:

function ThrowDemo(x)
{
    try
    {
        try
        {
        // Throw an exception that depends on the argument.
        if (x == 0)
            throw new Error(200, "x equals zero");
        else
            throw new Error(201, "x does not equal zero");
        }
        catch(e)
        {
            // Handle the exception.
            switch (e.number)
                {
                case 200:
                    ShowLine (e.message + " - handled locally.");
                    break;
                default:
                    // Throw the exception to a higher level.
                    throw e;
                }
        }
    }
    catch(e)
    {
        // Handle the higher-level exception.
        ShowLine (e.message + " - handled higher up.");
    }
}

function ShowLine(s)
    {
    document.write(s);
    document.write ("<br />");
    }

ThrowDemo (0);
ThrowDemo (1);

// Output:
//  x equals zero - handled locally.
//  x does not equal zero - handled higher up.

Requirements

Version 5

Change History

See Also

try...catch...finally Statement (Windows Scripting - JScript)
Error Object (Windows Scripting - JScript)