An exception is an occurrence in an application process that requires deviation from the program's normal flow.

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9
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6answers
2k views

Maybe monad vs exceptions

I wonder what are the advantages of Maybe monad over exceptions? It looks like Maybe is just explicit (and rather space-consuming) way of try..catch syntax. update Please note that I'm intentionally ...
3
votes
1answer
135 views

Etymology of “throw an exception“ [closed]

Why do we use the expression “throw an exception“ and not something like “generate“? Where was that term born and in which language?
1
vote
3answers
212 views

C API in C++ with RAII, two alternatives to implement error handling (Exceptions)

I have an API written in C, which produces a result by returning a pointer to allocated memory. For using it with C++ (C++11) I've wrapped the function calls in objects, which keep the result in a ...
4
votes
2answers
304 views

Nulls in every type and checked exceptions in Java?

I know that null being added to every type in Java is a source of much frustration regarding the language's type system. At the same time I generally hear complaining about checked exceptions - that ...
0
votes
5answers
195 views

Fail-fast paradigm overheads

Fail-fast seems like a right way since it simplifies bug detection. But it's a harm for performance cause of multiple checking the same thing at several levels of the system. Simple example. There is ...
3
votes
2answers
123 views

Inform caller or just let them deal with exception?

I'm not sure how to proceed in the following situation. say we have a function as so: def runsATask(codes): myDicts = [helperFunc(code) for code in codes] for item in myDicts: # some ...
3
votes
3answers
244 views

Does Exception Handling Violates “Program to Abstraction”? [duplicate]

I am talking based on experience with Java and C#. I do not know if other language have different exception handling implementation. In order to achieve loose coupling, we need our code being ...
40
votes
7answers
26k views

Why use try … finally without a catch clause?

The classical way to program is with try / catch but when is it appropriate to use try without catch? In Python the following appears legal and can make sense: try: #do work finally: #do ...
40
votes
10answers
3k views

Why are exceptions considered better than explicit error testing? [duplicate]

Possible Duplicate: Defensive Programming vs Exception Handling? if/else statements or exceptions I often come across heated blog posts where the author uses the argument: "exceptions vs ...
8
votes
3answers
1k views

Exceptions or Error codes

We are building a web service(SOAP, .Net) which would be talking to (mostly) native clients (windows, C++) and we are wondering what is the best way to communicate errors to the client (e.g. ...
2
votes
1answer
119 views

How to handle when one user deletes the object while the other has it opened in edit mode in a webapp?

I am developing a CRUD type web application. It is a project management system having projects, milestones, tasks, employees etc. Each employee has his/her own account to login and view the system. ...
1
vote
1answer
211 views

Either Monad and Exceptional Circumstances [duplicate]

I have a function returning an Either such as GetUserFromDb(int id). If the database is offline, should I catch the error in the function and wrap it in a failure / Left case or should I let it ...
0
votes
2answers
341 views

Is storing stack traces in database recommended?

The current system I am working on goes through a set of documents & performs some logic using the metadata of the document. If the metadata of a document is fishy..it throws an exception. The ...
54
votes
11answers
4k views

I've been told that Exceptions should only be used in exceptional cases. How do I know if my case is exceptional?

My specific case here is that the user can pass in a string into the application, the application parses it and assigns it to structured objects. Sometimes the user may type in something invalid. ...
5
votes
4answers
682 views

What's the reason exceptions are heavily used in managed (C# and Java) languages but not in C++? [closed]

AFAIK, a lot of C++ projects don't allow exceptions and deny them in coding guidelines. I have a lot of reasons, for example, exception is hard to handle correctly if your binary needs to be compiled ...
21
votes
2answers
1k views

Who designed exceptions?

Where did exceptions and exception handling come from? I like how .NET uses it, I like how C++ supports it (but libraries unfortunately use return code or is written in C instead). I know its pretty ...
2
votes
3answers
476 views

Layering Design Pattern in Java clean code style

As a Java developer, I am developing trying to use the clean code rules. But in my team we are facing a concrete problem: We have a business layer offering a service called "createObject", this ...
3
votes
3answers
202 views

Throwing exception from a property when my object state is invalid [duplicate]

I am aware that for the general case, the answer to "should I throw an exception from a property" is "generally don't, but in some special circumstances it is OK to do so". There is a Microsoft ...
36
votes
20answers
5k views

Is it ever ok to have an empty catch statement?

I thought about it and could not come up with an example. Why would somebody want to catch an exception and do nothing about it? Can you give an example? Maybe it is just something that should never ...
38
votes
7answers
2k views

Are there legitimate reasons for returning exception objects instead of throwing them?

This question is intended to apply to any OO programming language that supports exception handling; I am using C# for illustrative purposes only. Exceptions are usually intended to be raised when an ...
13
votes
2answers
978 views

What is a 'good number' of exceptions to implement for my library?

I've always wondered how many different exception classes I should implement and throw for various pieces of my software. My particular development is usually C++/C#/Java related, but I believe this ...
1
vote
4answers
451 views

What's the difference between the code inside a finally clause and the code located after catch clause?

My java code is just like below: public void check()throws MissingParamException{ ...... } public static void main(){ PrintWriter out = response.getWriter(); try { check(); } ...
6
votes
13answers
2k views

Should integer divide by zero halt execution? [closed]

I know that modern languages handle integer divide by zero as an error just like the hardware does, but what if we could design a whole new language? Ignoring existing hardware, what should a ...
2
votes
3answers
361 views

What code lays behind C++ exception?

In C and C++ you can return a single variable inside a function. Now in the case that variable is returning data, and not an error code, you can use exceptions. But how is that possible? If you data ...
2
votes
1answer
323 views

Why would one transform a checked exception to an unchecked exception? [duplicate]

My buddy told me today that some programmers transform a checked exception (e.g. EJBException, SQLException...) to an unchecked (RuntimeException?) My buddy explained a call stack where if you change ...
1
vote
2answers
261 views

Java exception redundancy

To what extent should one make exceptions redundant or atomic to a method. For instance, suppose I have a method public void authenticate(String username, String password) that calls private void ...
21
votes
4answers
7k views

Why do iterators in Python raise an exception?

Here's the syntax for iterators in Java (somewhat similar syntax in C#): Iterator it = sequence.iterator(); while (it.hasNext()) { System.out.println(it.next()); } Which makes sense. Here's ...
12
votes
6answers
2k views

What's the best way to manage error logging for exceptions?

Introduction If an error occurs on a website or system, it is of course useful to log it, and show the user a polite message with a reference code for the error. And if you have lots of systems, you ...
1
vote
3answers
209 views

Throwing an exception for errors that can be fixed

Say I have a class like this: public class MyObject { public List<string> MyCollection { get; set; } } And a method like this: public void DoSomething(MyObject object) { ...
6
votes
2answers
368 views

Where should I handle fatal exceptions

Suppose I have a controller that loads a file and hands it over to the processing. Should I handle the exception in the file loader and return Null if something is wrong, or should I throw the ...
1
vote
3answers
205 views

When is a catch clause empty [duplicate]

I saw lots of questions and explanations regarding empty catch clauses but I was never actually sure what "empty" means. Is a catch clause like this empty? It clearly isn't empty for the eye because ...
10
votes
4answers
1k views

Do you throw an argumentexception or argumentnullexception from private methods?

I was just reviewing some code I wrote a while back, and can see that I have a couple of private methods that throw argumentnullexceptions and/or argumentexceptions if there are issues with the ...
2
votes
3answers
127 views

Avoiding null in a controller

I'm trying to work through how to write this code. def get(params): """ Fetch a user's details, or 404 """ user = User.fetch_by_id(params['id']) if not user: abort(404) # ...
23
votes
9answers
8k views

Is it good practice to catch a checked exception and throw a RuntimeException?

I read some code of a colleague and found that he often catches various exceptions and then always throws a 'RuntimeException' instead. I always thought this is very bad practice. Am I wrong?
19
votes
12answers
2k views

How to teach Exception Handling for New Programmers?

How do you go about teaching Exception Handling to Programmers. All other things are taught easily - Data Structures, ASP.NET, WinForms, WPF, WCF - you name it, everything can be taught easily. With ...
21
votes
8answers
4k views

What to put in a try/catch? [duplicate]

Note on the question: this is not a duplicate, Efficient try / catch block usage? was asked after this one. The other question is the duplicate. I was wondering what was the best way to use ...
2
votes
4answers
187 views

How do you hide error handling? [duplicate]

Many people consider exceptions to be a problem because they create invisible paths through your code. For example in this snippet: function writeToFile(text, filename): filehandle = open(filename) ...
1
vote
1answer
259 views

Does this violate the using exceptions for flow control “rule”?

I plan to make use of this interface in a plug-in architecture. /// <summary> /// Generic interface allowing you to react to an event. /// You can block the event or just use it for ...
-1
votes
6answers
2k views

Converting an empty string to a number [closed]

If you are designing a function which should conver a string to an integer, how would you convert an empty string? The question is only about this one particular input value (empty string). Between ...
5
votes
8answers
959 views

Best Practice for Argument Checking

Say I have a web service with a method MyWebServiceMethod(string passedValue). The web service calls a method MyServiceMethod(string passedValue) where the value from the web service is passed along. ...
8
votes
8answers
922 views

Using a try-finally (without catch) vs enum-state validation

I have been reading the advice on this question about how an exception should be dealt with as close to where it is raised as possible. My dilemma on the best practice is whether one should use a ...
1
vote
2answers
650 views

Assertions vs Exceptions - is my understanding of the differences between the two correct? [duplicate]

Design By Contract uses preconditions and postconditions of the public methods in a class together to form a contract between the class and its clients. a) In code we implement preconditions ...
17
votes
5answers
4k views

should I throw exception from constructor?

I know I can throw exception from constructor in PHP but should I do it? For example, if a parameter's value is not as I expected it. Or should I defer throwing an exception till a method is invoked. ...
8
votes
5answers
6k views

throwing runtime exception in Java application

I am working as a contractor designing enterprise Java application for my client in the role of a technical lead. The application will be used by end users and there will be a support team who will ...
22
votes
3answers
880 views

Why is Option/Maybe considered a good idea and checked exceptions are not?

Some programming languages like e.g. Scala have the concept of Option types (also called Maybe), which can either contain a value or not. From what I've read about them they are considered widely to ...
1
vote
2answers
250 views

Wrapping specific checked exception in domain unchecked ones? [duplicate]

Uncle Bob says in Clean Code book that Unchecked Exceptions should be used. Now JDK has some checked exceptions: IOException, IllegalAccessException etc. which cannot be avoided. In my application ...
2
votes
7answers
627 views

better way to define an exception thrown by a method in Java?

I know how to define exceptions and all, but I'm not sure if the way I'm doing it is the most intuitive and readable by another users. I have a very simple method I've written that I want to throw an ...
16
votes
3answers
1k views

How many are too many nested function calls?

Quoted from MSDN about StackOverflowException: The exception that is thrown when the execution stack overflows because it contains too many nested method calls. Too many is pretty vague here. ...
13
votes
5answers
4k views

Are exceptions as control flow considered a serious antipattern? If so, Why?

Back in the late 90's I worked quite a bit with a code base that used exceptions as flow control. It implemented a finite state machine to drive telephony applications. Lately I am reminded of those ...
8
votes
3answers
6k views

Throwing an exception inside finally

Static code analyzers like Fortify "complain" when an exception might be thrown inside a finally block, saying that Using a throw statement inside a finally block breaks the logical progression ...