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Why is address zero used for the null pointer?
...emory, because it means freeing the pointer again isn't dangerous; when I call malloc it returns a pointer with the value zero if it can't get me memory; I use if (p != 0) all the time to make sure passed pointers are valid, etc.
...
How do you manage databases in development, test, and production?
...of good options. I wouldn't use the "restore a backup" strategy.
Script all your schema changes, and have your CI server run those scripts on the database. Have a version table to keep track of the current database version, and only execute the scripts if they are for a newer version.
Use a migr...
What is a clearfix?
...of laying out elements.)
A clearfix is a way for an element to automatically clear its child elements, so that you don't need to add additional markup. It's generally used in float layouts where elements are floated to be stacked horizontally.
The clearfix is a way to combat the zero-height cont...
How useful/important is REST HATEOAS ( maturity level 3)?
... members believe that a REST API has to be HATEOAS compliant and implement all Richardson's maturity levels ( http://martinfowler.com/articles/richardsonMaturityModel.html )!
...
Why does the 260 character path length limit exist in Windows?
... answered Dec 10 '09 at 11:45
vallivalli
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...
Extract a number from a string (JavaScript)
...ecific example,
var thenum = thestring.replace( /^\D+/g, ''); // replace all leading non-digits with nothing
in the general case:
thenum = "foo3bar5".match(/\d+/)[0] // "3"
Since this answer gained popularity for some reason, here's a bonus: regex generator.
function getre(str, num) {
...
Convert Python program to C/C++ code? [closed]
...t * stuff). And it will never get quite as fast as plain C because it's usually interfacing with Python (100% or more? only for plain numerical code that doesn't interface with Python at all for the most time!). But other than that, yes, it can get you a pretty devent speedup.
–...
C# Sortable collection which allows duplicate keys
... Use this Comparer e.g. with SortedLists or SortedDictionaries, that don't allow duplicate keys
/// </summary>
/// <typeparam name="TKey"></typeparam>
public class DuplicateKeyComparer<TKey>
:
IComparer<TKey> where TKey : IComparable
{
#...
Black transparent overlay on image hover with only CSS?
...0; left:0;
background:rgba(0,0,0,0.6);
opacity: 0;
transition: all 1s;
-webkit-transition: all 1s;
}
Use an opacity of 1 when hovering over the pseudo element in order to facilitate the transition:
.image:hover:after {
opacity: 1;
}
END RESULT HERE
If you want to add text on h...
How to validate an Email in PHP?
...hould be replaced by the preg family (PCRE Regex Functions). There are a small amount of differences, reading the Manual should suffice.
Update 1: As pointed out by @binaryLV:
PHP 5.3.3 and 5.2.14 had a bug related to
FILTER_VALIDATE_EMAIL, which resulted in segfault when validating
large ...