throw Statement (JScript 5.6) 

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

throw exception 

Remarks

The required exception argument can be any expression.

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

function TryCatchDemo(x){

   try {

      try {

      if (x == 0)   // Evalute argument.

         throw "x equals zero";   // Throw an error.

      else

         throw "x does not equal zero";   // Throw a different error.

      }

      catch(e) {   // Handle "x = 0" errors here.

         if (e == "x equals zero")   // Check for an error handled here.

            return(e + " handled locally.");   // Return object error message.

         else   // Can't handle error here.

            throw e;   // Rethrow the error for next

      }   // error handler.

   }

   catch(e) {   // Handle other errors here.

      return(e + " handled higher up.");   // Return error message.

   }

}

document.write(TryCatchDemo(0));

document.write(TryCatchDemo(1));

Requirements

Version 5

See Also

Reference

try...catch...finally Statement (JScript 5.6)