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What is an existential type?
... because of the existential operator (∃). I'm not sure what the point of it is, though. What's the difference between
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Regex to check whether a string contains only numbers [duplicate]
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var reg = /^\d+$/;
should do it. The original matches anything that consists of exactly one digit.
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Does a foreign key automatically create an index?
... a constraint, a relationship between two tables - that has nothing to do with an index per se.
But it is a known fact that it makes a lot of sense to index all the columns that are part of any foreign key relationship, because through a FK-relationship, you'll often need to lookup a relating table...
Remove secure warnings (_CRT_SECURE_NO_WARNINGS) from projects by default in Visual Studio
...gs that come up when using functions like scanf(). I found that you can do it by adding a line in the project option or a #define _CRT_SECURE_NO_WARNINGS in the beginning of the code.
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Padding within inputs breaks width 100%
Ok, so we know that setting padding to an object causes its width to change even if it is set explicitly. While one can argue the logic behind this, it causes some problems with some elements.
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How do I check if an object has a specific property in JavaScript?
...perty] or, even worse, x.key will give you completely misleading results.
It depends on what you're looking for. If you want to know if an object physically contains a property (and it is not coming from somewhere up on the prototype chain) then object.hasOwnProperty is the way to go. All modern br...
How to hash some string with sha256 in Java?
How can I hash some string with sha256 in Java? Does anybody know of any free library for this?
15 Answers
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How to initialize static variables
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PHP can't parse non-trivial expressions in initializers.
I prefer to work around this by adding code right after definition of the class:
class Foo {
static $bar;
}
Foo::$bar = array(…);
or
class Foo {
private static $bar;
static function init()
{
sel...
Replacing .NET WebBrowser control with a better browser, like Chrome?
... project I started a while back that thankfully got picked up by the community and turned into something wonderful.
The project wraps the Chromium Embedded Framework and has been used in a number of major projects including Rdio's Windows client, Facebook Messenger for Windows and Github for Window...
What is 'Currying'?
...The second statement defines a new function called add3 that will add 3 to its argument. This is what some people may call a closure. The third statement uses the add3 operation to add 3 to 4, again producing 7 as a result.
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