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How to check if PHP array is associative or sequential?
PHP treats all arrays as associative, so there aren't any built in functions. Can anyone recommend a fairly efficient way to check if an array contains only numeric keys?
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JS Client-Side Exif Orientation: Rotate and Mirror JPEG Images
...n to the EXIF orientation problem, correctly rotating/mirroring images for all 8 exif orientations. See the online demo of javascript exif orientation
The image is drawn onto an HTML5 canvas. Its correct rendering is implemented in js/load-image-orientation.js through canvas operations.
Hope this ...
Locate the nginx.conf file my nginx is actually using
...g on a client's server where there are two different versions of nginx installed. I think one of them was installed with the brew package manager (its an osx box) and the other seems to have been compiled and installed with the nginx packaged Makefile. I searched for all of the nginx.conf files on t...
The purpose of Model View Projection Matrix
...d space to camera space, projection from camera to screen.
If you compose all three, you can use the one result to map all the way from object space to screen space, making you able to work out what you need to pass on to the next stage of a programmable pipeline from the incoming vertex positions....
How to merge 2 List and removing duplicate values from it in C#
...return set. This is different
behavior to the Concat
method, which returns all the elements
in the input sequences including
duplicates.
List<int> list1 = new List<int> { 1, 12, 12, 5};
List<int> list2 = new List<int> { 12, 5, 7, 9, 1 };
List<int> ulist = list1.Union(l...
JOIN queries vs multiple queries
...ase. It depends on a lot of things. Jeff Atwood (founder of this site) actually wrote about this. For the most part, though, if you have the right indexes and you properly do your JOINs it is usually going to be faster to do 1 trip than several.
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Why can't enum's constructor access static fields?
...tatic fields and methods? This is perfectly valid with a class, but is not allowed with an enum.
5 Answers
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Cosmic Rays: what is the probability they will affect a program?
...rom Wikipedia:
Studies by IBM in the 1990s suggest that computers typically experience about one cosmic-ray-induced error per 256 megabytes of RAM per month.[15]
This means a probability of 3.7 × 10-9 per byte per month, or 1.4 × 10-15 per byte per second. If your program runs for 1 minute a...
Exception thrown inside catch block - will it be caught again?
...compile, to avoid that kind of erroneous situation. In general, you're not allowed to have a catch for a subclass after a catch of its superclass in the same try block.
– Chris Jester-Young
Aug 22 '16 at 23:32
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App Inventor 2 低功耗蓝牙(BLE) 硬件接入、数据通信及IO控制 - App Invent...
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