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The role of #ifdef and #ifndef
In this what is the role of #ifdef and #ifndef , and what's the output?
4 Answers
4...
Why is TypedReference behind the scenes? It's so fast and safe… almost magical!
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Short answer: portability.
While __arglist, __makeref, and __refvalue are language extensions and are undocumented in the C# Language Specification, the constructs used to implement them under the hood (vararg calling convention, TypedReference type, arglist, refanytype, mkanyref...
Cost of exception handlers in Python
...nt division or modulo by zero
So, as expected, not having any exception handler is slightly faster (but blows up in your face when the exception happens), and try/except is faster than an explicit if as long as the condition is not met.
But it's all within the same order of magnitude and unlikel...
Why is using “for…in” for array iteration a bad idea?
...5;
for (var x in a) {
// Shows only the explicitly set index of "5", and ignores 0-4
console.log(x);
}
/* Will display:
5
*/
Also consider that JavaScript libraries might do things like this, which will affect any array you create:
// Somewhere deep in your JavaScript...
How do I install Maven with Yum?
...g not to learn much about either yum or maven. I've inherited this code and I don't want to spend more time than I have to in this environment.
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Adjust list style image position?
...he actual content within the list item.
Using a combination of background and padding styles can create something that looks similar e.g.
li {
background: url(images/bullet.gif) no-repeat left top; /* <-- change `left` & `top` too for extra control */
padding: 3px 0px 3px 10px;
/* res...
What is the difference between Nexus and Maven?
What is the difference between Nexus and Maven ?
3 Answers
3
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Linux: compute a single hash for a given folder & contents?
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If there is a whole directory tree, you're probably better off using find and xargs. One possible command would be
find path/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/folde...
parseInt(null, 24) === 23… wait, what?
Alright, so I was messing around with parseInt to see how it handles values not yet initialized and I stumbled upon this gem. The below happens for any radix 24 or above.
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Associative arrays in Shell scripts
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To add to Irfan's answer, here is a shorter and faster version of get() since it requires no iteration over the map contents:
get() {
mapName=$1; key=$2
map=${!mapName}
value="$(echo $map |sed -e "s/.*--${key}=\([^ ]*\).*/\1/" -e 's/:SP:/ /g' )"
}
...