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Matching an empty input box using CSS

...e present in the input tag. Tested in Chrome - not sure if this counts for all browsers. – Berend Mar 17 '17 at 6:23 10 ...
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Heroku NodeJS http to https ssl forced redirect

... to the accepted answer above, but: Ensures you use "app.use" (for all actions, not just get) Explicitly externalises the forceSsl logic into a declared function Does not use '*' with "app.use" - this actually failed when I tested it. Here, I only want SSL in production. (Change as ...
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Check if an array is empty or exists

...y" !== "array" typeof array == "undefined"; // => true Case Null Generally speaking, null is state of lacking a value. For example a variable is null when you missed or failed to retrieve some data. array = searchData(); // can't find anything array == null; // => true Case Not a...
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How do I determine k when using k-means clustering?

...nder Selb in Pattern Analysis and Applications vol. 2, p. 59-72, 1999. Finally, you can start with one cluster, then keep splitting clusters until the points assigned to each cluster have a Gaussian distribution. In "Learning the k in k-means" (NIPS 2003), Greg Hamerly and Charles Elkan show some ...
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How to retrieve the dimensions of a view?

... getWidth() always return 0. This happens when I format the grid dynamically and also when I use an XML version. 16 An...
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What is the difference between memoization and dynamic programming?

...he computations of the subproblems overlap. Dynamic programming is typically implemented using tabulation, but can also be implemented using memoization. So as you can see, neither one is a "subset" of the other. A reasonable follow-up question is: What is the difference between tabulation (th...
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Update Row if it Exists Else Insert Logic with Entity Framework

...s.AddObject(myEntity); } // Attached object tracks modifications automatically context.SaveChanges(); If you can use any knowledge about the object's key you can use something like this: if (myEntity.Id != 0) { context.MyEntities.Attach(myEntity); context.ObjectStateManager.ChangeObject...
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How do you convert a jQuery object into a string?

...est').clone()).html(); This is explained in more depth here, but essentially you make a new node to wrap the item of interest, do the manipulations, remove it, and grab the HTML. If you're just after a string representation, then go with new String(obj). Update I wrote the original answer in 2...
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I need to pop up and trash away a “middle” commit in my master branch. How can I do it?

... Rebase or revert are the options. Rebase will actually remove the commit from the history so it will look like that second commit never existed. This will be a problem if you've pushed the master branch out to any other repos. If you try to push after a rebase in this case, ...
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How do I handle the window close event in Tkinter?

... Tkinter supports a mechanism called protocol handlers. Here, the term protocol refers to the interaction between the application and the window manager. The most commonly used protocol is called WM_DELETE_WINDOW, and is used to define what happens when th...