I always thought this was one of the better articles on the subject. It includes the following example that I think makes it clear and includes the frequently overlooked @@trancount which is needed for reliable nested transactions PRINT ‘BEFORE TRY’ BEGIN TRY BEGIN TRAN PRINT ‘First Statement in the TRY block’ INSERT INTO dbo.Account(AccountId, Name … Read more
It’s fine, although if your exception handling logic is that complex, you might consider breaking it out into its own function.
Use Uri.TryCreate to create a new Uri object only if your url string is a valid URL. If the string is not a valid URL, TryCreate returns false. string myString = “http://someUrl”; Uri myUri; if (Uri.TryCreate(myString, UriKind.RelativeOrAbsolute, out myUri)) { //use the uri here } UPDATE TryCreate or the Uri constructor will happily accept strings … Read more
It seems to me that this topic is very strange and confused. Could someone lights me up? Definitely. I’m not a PHP user, but I might have a little insight after having worked with try/catch in ActionScript, Java, and JavaScript. Bear in mind though, that different languages and platforms encourage different uses for try/catch. That … Read more
You need to implement Do Try Catch error handling as follow: import UIKit import PlaygroundSupport PlaygroundPage.current.needsIndefiniteExecution = true extension URL { func asyncDownload(completion: @escaping (_ data: Data?, _ response: URLResponse?, _ error: Error?) -> ()) { URLSession.shared .dataTask(with: self, completionHandler: completion) .resume() } } let jsonURL = URL(string: “https://api.whitehouse.gov/v1/petitions.json?limit=100”)! let start = Date() jsonURL.asyncDownload { … Read more
It does not give a compilation error because it is allowed by the Java Language Specification. However, it gives a warning message because including a return statement in the finally block is usually a bad idea. What happens in your example is the following. The return statement in the try block is executed. However, the … Read more
One thing to consider is that the cost of a try block where no exception is thrown is a different question from the cost of actually throwing and catching an exception. If exceptions are only thrown in failure cases, you almost certainly don’t care about performance, since you won’t fail very many times per execution … Read more
Why does old code do this? Historically, older (pre 2013) promise libraries ‘swallowed’ unhandled promise rejections you have not handled yourself. This has not been the case in anything written since then. What happens today? Browsers and Node.js already automatically log uncaught promise rejections or have behaviour for handling them and will log them automatically. … Read more
The sys module provides some functions for post-hoc examining of exceptions: sys.last_type, sys.last_value, and sys.last_traceback. sys.last_value is the one you’re looking for.
Since Exception is a checked exception, you either: Have to catch the exception in a try…catch statement, or Declare the exception to be thrown in the method itself. What you have up there works fine, but my personal preference is to declare the exception to be thrown. This way, if an exception I’m not expecting … Read more