[removed] What's more efficient, IF block or TRY/CATCH?

Question

I\'d love some other opinions on what\'s more efficient in this code. Basically in the following code, there\'s a setInterval loop and I need 4 requirements to be true befor

Answer 1

Aside from the answers given, I want to add some thoughts on this subject.

Exceptions that are unforeseen, i.e. the runtime throws an exception, should not be caught with try ... catch because you want to read the message that is thrown in the console.

Try ... catch should IMO be thrown when an exception occurs that your application can foresee in your application logic and you want to perform some custom actions when they do. I.e. you want to be descriptive about it being an exception, and it's not part of the happy flow of the application logic.

For example, you could have a method that validates user input so you could have an isValid method that returns a boolean in which case you would use if ... then.

On the other hand if your performing a certain process, and you know that a certain exception can occur that interrupts the happy flow and you want to handle this, I feel that it is better to throw an exception.

As abstract example, you could have methods that implements some business rules.
Instead of validating every business rule for validity, you could have one custom Exception containing dynamic metadata that can be thrown by each of these methods when validity is breached and handle them appropriately, and continue the happy flow otherwise.
This would translate into something like:

throw new BusinessValidationException(TAG, 'Reason for the validation');

Which IMO is much more descriptive than:

if (!checkValidityBusinessRule()) 
    // doSomething 

For a series of business rules.

As for the example, it's my humble opinion that this check shouldn't be happening in the first place and that the given checks are true by default for implementing the method.

if(typeof jQuery == 'function' && typeof nav == 'object' && typeof pageid != 'undefined' && typeof document.getElementById('leftnav') == 'object')

What it means is that you must declaratively ensure that given conditions are true before invoking the given method with side-effects, taking away the necessity to perform the checks at all.
If it so happens that one of the conditions is false, then it will throw an exception to the console, which is actually what you want because as a developer it means that something in your application logic or lifecycle is broken.

My 2 cents, I hope they make sense.