1throw new Error('Whoops!')

1FactoryController.prototype.create = function (callback) {
2    //The throw is working, and the exception is returned.
3    throw new Error('An error occurred'); //outside callback 
4    try {
5        this.check(function (check_result) {
6            callback(check_result);
7        });
8    } catch (ex) {
9        throw new Error(ex.toString());
10    }
11}
12
13FactoryController.prototype.create = function (callback) {
14    try {
15        this.check(function (check_result) {
16            //The throw is not working on this case to return the exception to the caller(parent)
17            throw new Error('An error occurred'); //inside callback 
18        });
19    } catch (ex) {
20        throw new Error(ex.toString());
21    }
22}

1try {
2  throw "I'm Evil"
3  console.log("You'll never reach to me", 123465)
4} catch (e) {
5  console.log(e); // I'm Evil
6}

1#Throw new error:
2
3The difference between 'throw new Error' and 'throw someObject' in javascript is that throw new Error wraps the error passed to it in the following format −
4
5{ name: 'Error', message: 'String you pass in the constructor' }
6
7The throw someObject will throw the object as is and will not allow any further code execution from the try block, ie same as throw new Error.
8
9Here is a good explanation about The Error object and throwing your own errors
10
11The Error Object
12
13Just what we can extract from it in an event of an error? The Error object in all browsers support the following two properties:
14
15name: The name of the error, or more specifically, the name of the constructor function the error belongs to.
16
17message: A description of the error, with this description varying depending on the browser.
18
19Six possible values can be returned by the name property, which as mentioned correspond to the names of the error's constructors. They are:
20
21Error Name          Description
22
23EvalError           An error in the eval() function has occurred.
24
25RangeError          Out of range number value has occurred.
26
27ReferenceError      An illegal reference has occurred.
28
29SyntaxError         A syntax error within code inside the eval() function has occurred.
30                    All other syntax errors are not caught by try/catch/finally, and will
31                    trigger the default browser error message associated with the error. 
32                    To catch actual syntax errors, you may use the onerror event.
33
34TypeError           An error in the expected variable type has occurred.
35
36URIError            An error when encoding or decoding the URI has occurred 
37                   (ie: when calling encodeURI()).
38Throwing your own errors (exceptions)
39
40Instead of waiting for one of the 6 types of errors to occur before control is automatically transferred from the try block to the catch block, you can also explicitly throw your own exceptions to force that to happen on demand. This is great for creating your own definitions of what an error is and when control should be transferred to catch.

1app.get('/', function (req, res, next) {
2  Promise.resolve().then(function () {
3    throw new Error('BROKEN')
4  }).catch(next) // Errors will be passed to Express.
5})
6

1throw new Error("Your error message");