It is clearly a compiler bug, and it was introduced in C# 3.0 — right around the time that I heavily refactored the reachability checker. This is probably my bad, sorry. The bug is completely benign; basically, we just forgot a case in the warning reporter. We generate the reachability information correctly; as others have … Read more
Declarations of var variables get hoisted – the variable name initialization gets hoisted to the top of the containing function (or, if no function, to the top of the outer block). So var withVar = (function() {throw ‘error!’})() is parsed by the interpreter as var withVar; withVar = (function() {throw ‘error!’})() The same is not … Read more
Throwing twice in the same method is probably a special case – I’ve not been able to create a stack trace where different lines in the same method follow each other. As the word says, a “stack trace” shows you the stack frames that an exception traversed. And there is only one stack frame per … Read more
I would recommend you never throw NullPointerException by yourself. The main reason not to do this, as Thorbjørn Ravn Andersen says in a comment below, is that you don’t wan’t to mix ‘real, bad NPEs’ with NPEs thrown intentionally. So, until you’re confident that you’re able to recognize ‘valid’ NPE, I’d recommend to use IllegalArgumentException … Read more
Exception specifiers were deprecated because exception specifiers are generally a terrible idea. noexcept was added because it’s the one reasonably useful use of an exception specifier: knowing when a function won’t throw an exception. Thus it becomes a binary choice: functions that will throw and functions that won’t throw. noexcept was added rather than just … Read more
The 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 − { name: ‘Error’, message: ‘String you pass in the constructor’ } The throw someObject will throw the object as is and will not allow any further code execution … Read more
Exception specifiers were deprecated because exception specifiers are generally a terrible idea. noexcept was added because it’s the one reasonably useful use of an exception specifier: knowing when a function won’t throw an exception. Thus it becomes a binary choice: functions that will throw and functions that won’t throw. noexcept was added rather than just … Read more
Yes, throwing an exception from the failed constructor is the standard way of doing this. Read this FAQ about Handling a constructor that fails for more information. Having a init() method will also work, but everybody who creates the object of mutex has to remember that init() has to be called. I feel it goes … Read more
You should catch the exception when you are in the method that knows what to do. For example, forget about how it actually works for the moment, let’s say you are writing a library for opening and reading files. So you have a class, say: public class FileInputStream extends InputStream { public FileInputStream(String filename) { … Read more
throws : Used when writing methods, to declare that the method in question throws the specified (checked) exception. As opposed to checked exceptions, runtime exceptions (NullPointerExceptions etc) may be thrown without having the method declare throws NullPointerException. throw: Instruction to actually throw the exception. (Or more specifically, the Throwable). The throw keyword is followed by … Read more