JavaScript Error Handling

Try Catch

• try...catch works synchronously
  • To catch an exception inside a scheduled function, try...catch must be inside that function:

setTimeout(function() {
  try {
    noSuchVariable; // try...catch handles the error!
  } catch {
    alert( "error is caught here!" );
  }
}, 1000);

• try...catch only works for runtime errors
  • For try...catch to work, the code must be runnable. In other words, it should be valid JavaScript.

Throw Operator

throw <error object>
let error = new Error(message);
let error = new SyntaxError(message);
let error = new ReferenceError(message);

Finally

The finally clause is a great place to finish the measurements no matter what.

Variables are local inside try...catch...finally