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iPhone viewWillAppear not firing

... If you use a navigation controller and set its delegate, then the view{Will,Did}{Appear,Disappear} methods are not invoked. You need to use the navigation controller delegate methods instead: navigationController:willShowViewController:animated: navigationCo...
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Service vs IntentService in the Android platform

... can be done with an IntentService that cannot be done with a Service (and vice-versa)? 11 Answers ...
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How are echo and print different in PHP? [duplicate]

Is there any major and fundamental difference between these two functions in PHP? 5 Answers ...
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What is the best way to trigger onchange event in react js

... For React 16 and React >=15.6 Setter .value= is not working as we wanted because React library overrides input value setter but we can call the function directly on the input as context. var nativeInputValueSetter = Object.getOwnProp...
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Can hash tables really be O(1)?

... You have two variables here, m and n, where m is the length of the input and n is the number of items in the hash. The O(1) lookup performance claim makes at least two assumptions: Your objects can be equality compared in O(1) time. There will be few ha...
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Which concurrent Queue implementation should I use in Java?

... Basically the difference between them are performance characteristics and blocking behavior. Taking the easiest first, ArrayBlockingQueue is a queue of a fixed size. So if you set the size at 10, and attempt to insert an 11th element, the insert statement will block until another thread remove...
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How to delete duplicates on a MySQL table?

... Notice: this would keep the oldest duplicate record and would erase the newer ones. If you want to keep the newest you cannot do this with ALTER IGNORE. – Haralan Dobrev Oct 1 '12 at 10:26 ...
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What is the difference between Pan and Swipe in iOS?

...antics: a pan recognizer looks for the beginning of translational movement and continues to report movement in any direction over time, while a swipe recognizer makes an instantaneous decision as to whether the user's touches moved linearly in the required direction. By default, no two recognizers...
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Positions fixed doesn't work when using -webkit-transform

I am using -webkit-transform (and -moz-transform / -o-transform) to rotate a div. Also have position fixed added so the div scrols down with the user. ...
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Count(*) vs Count(1) - SQL Server

Just wondering if any of you people use Count(1) over Count(*) and if there is a noticeable difference in performance or if this is just a legacy habit that has been brought forward from days gone past? ...