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Why does one often see “null != variable” instead of “variable != null” in C#?
...r (and is indeed legal code):
// Probably wrong
if (x = 5)
when you actually probably meant
if (x == 5)
You can work around this in C by doing:
if (5 == x)
A typo here will result in invalid code.
Now, in C# this is all piffle. Unless you're comparing two Boolean values (which is rare, IME...
log4j logging hierarchy order
...assigns a priority/severity level to the logging message. If the logging really takes effect (the message will be visible) depends on the effective logging level of the logger being used.
– Wolf
Oct 6 '17 at 6:18
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Counting the number of elements with the values of x in a vector
...
Don't forget about potential floating point issues, especially with table, which coerces numbers to strings.
– hadley
Dec 17 '09 at 18:10
4
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Combined area of overlapping circles
...
Find all circle intersections on the outer perimeter (e.g. B,D,F,H on the following diagram). Connect them together with the centres of the corresponding circles to form a polygon. The area of the union of the circles is the area ...
Linux: compute a single hash for a given folder & contents?
...to/folder -type f -print0 | sort -z | xargs -0 sha1sum | sha1sum
And, finally, if you also need to take account of permissions and empty directories:
(find path/to/folder -type f -print0 | sort -z | xargs -0 sha1sum;
find path/to/folder \( -type f -o -type d \) -print0 | sort -z | \
xargs -0...
Why is #!/usr/bin/env bash superior to #!/bin/bash?
...or example, on my OpenBSD system, it's in /usr/local/bin, since it was installed as an optional package.
If you are absolutely sure bash is in /bin and will always be, there's no harm in putting it directly in your shebang—but I'd recommend against it because scripts and programs all have lives b...
SQL - The conversion of a varchar data type to a datetime data type resulted in an out-of-range valu
...s with the time zone setting. Specify in other formats like mm/dd/yyyy (usually works).
Specifying the date as 30/12/2013 resulted in the error for me. However, specifying it as mm/dd/yyyy format worked.
If you need to convert your input the you can try looking into the CONVERT method.
Syntax i...
What is your preferred style for naming variables in R? [closed]
...
Good previous answers so just a little to add here:
underscores are really annoying for ESS users; given that ESS is pretty widely used you won't see many underscores in code authored by ESS users (and that set includes a bunch of R Core as well as CRAN authors, excptions like Hadley notwithsta...
What are the differences between Autotools, Cmake and Scons?
...
In truth, Autotools' only real 'saving grace' is that it is what all the GNU projects are largely using.
Issues with Autotools:
Truly ARCANE m4 macro syntax combined with verbose, twisted shell scripting for tests for "compatibility", etc.
If you're not paying attention, you will mess u...
Google Guice vs. PicoContainer for Dependency Injection
...need to know about Pico. It's only the wiring that needs to know (true for all DI frameworks).
Guice - Guice now supports the standard JSR 330 annotations, so you do not need Guice specific annotations in your code anymore. Spring also supports these standard annotations. The argument that the Guice...