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JavaScript

Posted by Ryan Scharfer
Ryan Scharfer
Courses Plus Student 12,537 Points

JS Errors : What is the advantage of throwing objects over throwing strings?

I am starting to learn about Javascript errors and how to throw exceptions. I haven't quite figured out why one should throw an object. Why wouldn't a string be sufficient?

Why is this preferred ......

function addTwoNumbers(a,b){

  if (typeof a === "number" && typeof b ==="number")
    return a+b;
  else throw new Error("addTwoNumbers(): One or both of the arguments is not a number.");
}

over this?

function addTwoNumbers(a,b){

  if (typeof a === "number" && typeof b ==="number")
    return a+b;
  else throw "addTwoNumbers(): One or both of the arguments is not a number.";
}

2 Answers

Colin Bell
Colin Bell
29,679 Points

In short, it helps immensely when debugging.

Here is a good write up explaining it: A String is not an Error

And another: The art of throwing JavaScript errors

Ryan Scharfer
PLUS
Ryan Scharfer
Courses Plus Student 12,537 Points
Ryan Scharfer
Ryan Scharfer
Courses Plus Student 12,537 Points

Thanks Colin. : )