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Understand the “Decorator Pattern” with a real world example

... sell few pizza varieties and they will also provide toppings in the menu. Now imagine a situation wherein if the pizza shop has to provide prices for each combination of pizza and topping. Even if there are four basic pizzas and 8 different toppings, the application would go crazy maintaining all t...
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Why there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT clause?

...TAMP and ON UPDATE CURRENT_TIMESTAMP clauses. In addition, these clauses now can be used with DATETIME column definitions. For more information, see Automatic Initialization and Updating for TIMESTAMP and DATETIME. http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-5.html ...
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Subtract 7 days from current date

... use dateByAddingTimeInterval method: NSDate *now = [NSDate date]; NSDate *sevenDaysAgo = [now dateByAddingTimeInterval:-7*24*60*60]; NSLog(@"7 days ago: %@", sevenDaysAgo); output: 7 days ago: 2012-04-11 11:35:38 +0000 Hope it helps ...
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When is JavaScript's eval() not evil?

...-looking command". So, when is it OK to use something dangerous? When you know what the danger is, and when you're taking the appropriate precautions. To the point, let's look at the dangers in the use of eval(). There are probably many small hidden dangers just like everything else, but the two bi...
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Fixed position but relative to container

... Short answer: no. (It is now possible with CSS transform. See the edit below) Long answer: The problem with using "fixed" positioning is that it takes the element out of flow. thus it can't be re-positioned relative to its parent because it's as if ...
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What is the reason behind cbegin/cend?

...ref = vec; std::for_each(vec_ref.begin(), vec_ref.end(), SomeFunctor()); Now, we introduce cbegin/cend: std::for_each(vec.cbegin(), vec.cend(), SomeFunctor()); Now, we have syntactic assurances that SomeFunctor cannot modify the elements of the vector (without a const-cast, of course). We expli...
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What is the difference between “word-break: break-all” versus “word-wrap: break-word” in CSS

... Note that the W3C link that @squareman mentioned is now w3.org/TR/css-text-3/#overflow-wrap-property – Charles Wood Jun 26 '19 at 18:26 ...
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jQuery event for images loaded

...ul Irish, the canonical plugin for detecting image load complete events is now at: https://github.com/desandro/imagesloaded share | improve this answer | follow ...
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What does Expression.Quote() do that Expression.Constant() can’t already do?

... is a factory for adders that are bound to the outer lambda's parameter. Now, suppose we wish to represent this as an expression tree that will later be compiled and executed. What should the body of the expression tree be? It depends on whether you want the compiled state to return a delegate or ...
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how to solve “ruby installation is missing psych” error?

...ven though it was successfully installed, it complained about libyaml. and now every time i wanna install a gem (say rails) this warning shows up: ...