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Calling virtual functions inside constructors
...l of the hierarchy in the current constructor and no further.
The C++ FAQ Lite covers this in section 23.7 in pretty good detail. I suggest reading that (and the rest of the FAQ) for a followup.
Excerpt:
[...] In a constructor, the virtual call mechanism is disabled because overriding from derived...
Using try vs if in python
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You often hear that Python encourages EAFP style ("it's easier to ask for forgiveness than permission") over LBYL style ("look before you leap"). To me, it's a matter of efficiency and readability.
In your example (say that instead of returning a list or an empty string, the...
Using an HTML button to call a JavaScript function
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There are a few ways to handle events with HTML/DOM. There's no real right or wrong way but different ways are useful in different situations.
1: There's defining it in the HTML:
<input id="clickMe" type="button" value="clickme" onclick="doFunction();" /&g...
Android : difference between invisible and gone?
What is the difference between invisible and gone for the View visibility status?
8 Answers
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How to use index in select statement?
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If you want to test the index to see if it works, here is the syntax:
SELECT *
FROM Table WITH(INDEX(Index_Name))
The WITH statement will force the index to be used.
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Swift: Pass array by reference?
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edited Nov 15 '17 at 21:23
iwasrobbed
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Recommended way of making React component/div draggable
I want to make a draggable (that is, repositionable by mouse) React component, which seems to necessarily involve global state and scattered event handlers. I can do it the dirty way, with a global variable in my JS file, and could probably even wrap it in a nice closure interface, but I want to kno...
Why is there a `null` value in JavaScript?
...ll value in JS" - there is a null value of some sort in most languages and it is generally considered very useful.
The question is, "why is there an undefined value in JS". Major places where it is used:
when you declare var x; but don't assign to it, x holds undefined;
when your function gets fe...
Why compile Python code?
...u compile a Python script? You can run them directly from the .py file and it works fine, so is there a performance advantage or something?
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What is Linux’s native GUI API?
...ed the X Window System, which defines a device independent way of dealing with screens, keyboards and pointer devices.
X Window defines a network protocol for communication, and any program that knows how to "speak" this protocol can use it. There is a C library called Xlib that makes it easier to ...