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?: operator (the 'Elvis operator') in PHP
... bar will only be evaluated once.
You can also use this to do a "self-check" of foo as demonstrated in the code example you posted:
foo = foo ?: bar;
This will assign bar to foo if foo is null or falsey, else it will leave foo unchanged.
Some more examples:
<?php
var_dump(5 ?: 0); // 5
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Does Python SciPy need BLAS?
...ns. To build SciPy (and NumPy) on operating systems without precompiled packages of the required libraries, you must build and then statically link to the Fortran libraries BLAS and LAPACK:
mkdir -p ~/src/
cd ~/src/
wget http://www.netlib.org/blas/blas.tgz
tar xzf blas.tgz
cd BLAS-*
## NOTE: The s...
Where do I find the definition of size_t?
I see variables defined with this type but I don't know where it comes from, nor what is its purpose. Why not use int or unsigned int? (What about other "similar" types? Void_t, etc).
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Which is the fastest algorithm to find prime numbers?
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A very fast implementation of the Sieve of Atkin is Dan Bernstein's primegen. This sieve is more efficient than the Sieve of Eratosthenes. His page has some benchmark information.
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How to convert CFStringRef to NSString?
... them.
For example:
CFStringRef aCFString = (CFStringRef)aNSString;
works perfectly and transparently. Likewise:
NSString *aNSString = (NSString *)aCFString;
The previous syntax was for MRC. If you're using ARC, the new casting syntax is as follows:
NSString *aNSString = (__bridge NSString *...
Bash: Syntax error: redirection unexpected
...swered Mar 17 '10 at 13:05
John KugelmanJohn Kugelman
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In c# what does 'where T : class' mean?
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Andy RoseAndy Rose
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What are the best practices for using Assembly Attributes?
...with multiple project. I am trying to optimize AssemblyInfo.cs files by linking one solution wide assembly info file. What are the best practices for doing this? Which attributes should be in solution wide file and which are project/assembly specific?
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A potentially dangerous Request.Form value was detected from the client
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I think you are attacking it from the wrong angle by trying to encode all posted data.
Note that a "<" could also come from other outside sources, like a database field, a configuration, a file, a feed and so on.
Furthermore, "&...
Filter data.frame rows by a logical condition
...rame based on a logical condition. Let's suppose that I have data frame like
9 Answers
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