oop - Inheritance in .NET is useless? -

-

i'm quite new .net programming. know .net programming 100% object oriented. intriguing paragraph read in book asp.net 4 states

inheritance less useful might expect. in ordinary application, classes use containment , other relationships instead of inheritance, because inheritance can complicate life needlessly without delivering many benefits. dan appleman, renowned .net programmer, once described inheritance “the coolest feature you’ll never use.”

i'm little bit confused here , need .net programmers tell me should take , should leave.

edit

please people understand question, first author didn't literally "inheritance in .net useless", way zip hole question in words fit title. second, book apress , title is: "beginning asp.net 4 in c# 2010" page 72.

ouch. inheritance not useful, it's core concept, every class inherits system.object (not sure if there hacks/clr stuff doesn't).

also in technologies asp.net mvc use inheritance (by creating base controller).

everyone uses inheritance time, of time without realizing it. there not inheritance in smaller/medium sized apps, instead interfaces used, example dependency injection. however, pretty every non-trivial application tends have base class floating around somewhere other classes inherit.

i'm guessing that's author means, decision between defining base class or interfaces. microsoft recommends base classes, in real life interfaces seem more common. since c# not support multiple inheritance (a class has more 1 base class) interfaces offer more flexibility @ cost of not being able centralize common code or enforce constructors.


Comments

Post a Comment

Popular posts from this blog

javascript - Enclosure Memory Copies -

-
function myclass() { //lots , lots of vars , code here. this.bar = function() { //do numerous enclosed myclass vars } this.foo = function() { alert('hello'); //don't enclosed variables. } } each instance of myclass gets own copy of bar , foo, why prototyped methods use less memory. however, know more memory use of inner methods. it seems obvious me (1) below must true. agree? not distinct myclass instances have own distinct copies of bar, must have own distinct copies of myclass enclosure. (or else how bar method keep myclass variables straight on per instance basis?) now (2) question i'm after. since inner foo method doesn't use in myclass enclosure natural qustion is: javascript smart enough not keep myclass enclosure in memory use of foo? this depend entirely on implementation not language. naive implementations keep far more around others. answer true e.g. v8 (chrome's js engine) may not true spider...
Read more

php - Replacing tags in braces, even nested tags, with regex -

-
example preg_replace('/\{[a-za-z.,\(\)0-9]+\}/', 'replaced', 'lorem ipsum dolor sit {tag1({tag2()})}, consectetur adipiscing elit.'); the result: lorem ipsum dolor sit {tag1(replaced)}, consectetur adipiscing elit. question as can see "tag2" has been replaced, want replace "tag1" know how can this? (in cases might this: {tag1({tag2({tag3()})})}) , on.) btw using preg_replace_callback, easier show preg_replace here site can test code: http://www.spaweditor.com/scripts/regex/index.php you need add curly braces character set. here's pattern used: /\{[a-za-z.,\(\)\{\}0-9]+\}/ and here result: "lorem ipsum dolor sit replaced, consectetur adipiscing elit."
Read more