I have been quite curious about how javascript reacts to errors(like ReferenceError, for example). When it encounters a runtime error, it seems to return from the function that it is called in which, in turn, fails the function it was called in.
Does it consequently fail all the functions in the frame stack? (This is more of a question out of academic curiosity. Hope somebody can explain it to me?)
Thanks!
JavaScript exception handling is much the same as other languages' error handling - it will throw an error up the call stack until handled by the catch of a try block. If there is no try/catch, then the current execution will stop.
All the function calls below the catch will be exited - they won't return anything, and the following lines of code will not be executed.
It continues up the call stack until it reaches a a try...catch block.
You can see a simple example on JSFiddle.
It returns an Object of the error, and like most Objects, it has has methods and properties
try {
a/1;
} catch(err) {
console.log(err.name) //ReferenceError
console.log(err.message); //a is not defined
console.log(err.constructor); //ReferenceError() { [native code] }
console.log(err.toString()); //ReferenceError: a is not defined
console.log(err.stack)
/*
ReferenceError: a is not defined
at errCatch (<anonymous>:3:11)
at <anonymous>:1:11
*/
}
note, console.log(Object) is the same as Object.toString(). Hope it helps.
