Search results
Results From The WOW.Com Content Network
Versioning: A method may be declared to throw exceptions X and Y. In a later version of the code, one cannot throw exception Z from the method, because it would make the new code incompatible with the earlier uses. Checked exceptions require the method's callers to either add Z to their throws clause or handle the exception.
An exception handling mechanism allows the procedure to raise an exception [2] if this precondition is violated, [1] for example if the procedure has been called on an abnormal set of arguments. The exception handling mechanism then handles the exception. [3] The precondition, and the definition of exception, is subjective.
Exception swallowing can also happen if the exception is handled and rethrown as a different exception, discarding the original exception and all its context. In this C# example, all exceptions are caught regardless of type, and a new generic exception is thrown, keeping only the message of the original exception.
The Perl mechanism for exception handling uses die to throw an exception when wrapped inside an eval {...}; block. After the eval, the special variable $@ contains the value passed from die. Perl 5.005 added the ability to throw objects as well as strings. This allows better introspection and handling of types of exceptions.
Exception chaining, or exception wrapping, is an object-oriented programming technique of handling exceptions by re-throwing a caught exception after wrapping it inside a new exception. The original exception is saved as a property (such as cause) of the new exception. The idea is that a method should throw exceptions defined at the same ...
C# only supports unchecked exceptions. Checked exceptions force the programmer to either declare the exception thrown in a method, or to catch the thrown exception using a try-catch clause. Checked exceptions can encourage good programming practice, ensuring that all errors are dealt with.
A Runnable, however, does not return a result and cannot throw a checked exception. [4] Each thread can be scheduled [5] on a different CPU core [6] or use time-slicing on a single hardware processor, or time-slicing on many hardware processors. There is no general solution to how Java threads are mapped to native OS threads.
In object-oriented computer programming, a null object is an object with no referenced value or with defined neutral (null) behavior.The null object design pattern, which describes the uses of such objects and their behavior (or lack thereof), was first published as "Void Value" [1] and later in the Pattern Languages of Program Design book series as "Null Object".