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));