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What's the difference between eval, exec, and compile?
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The short answer, or TL;DR
Basically, eval is used to evaluate a single dynamically generated Python expression, and exec is used to execute dynamically generated Python code only for its side effects.
eval and exec have these two differences:
eval accep...
JavaScript check if variable exists (is defined/initialized)
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You want the typeof operator. Specifically:
if (typeof variable !== 'undefined') {
// the variable is defined
}
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Calculate distance between two points in google maps V3
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@EmanuelePaolini - Mathematically, atan2(sqrt(a),sqrt(1-a)) = asin(sqrt(a)) = acos(sqrt(1-a)), but the atan2 version remains numerically better conditioned for all values of a.
– ChrisV
Dec 19 '14 at 18:00
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Converting double to string
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double total = 44;
String total2 = String.valueOf(total);
This will convert double to String
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Calculate distance between 2 GPS coordinates
...y solution:
#include <math.h>
#include "haversine.h"
#define d2r (M_PI / 180.0)
//calculate haversine distance for linear distance
double haversine_km(double lat1, double long1, double lat2, double long2)
{
double dlong = (long2 - long1) * d2r;
double dlat = (lat2 - lat1) * d2r;
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Looping through a hash, or using an array in PowerShell
... how:
$hash = @{
a = 1
b = 2
c = 3
}
$hash.Keys | % { "key = $_ , value = " + $hash.Item($_) }
Output:
key = c , value = 3
key = a , value = 1
key = b , value = 2
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How do I use Notepad++ (or other) with msysgit?
...he '-multiInst' option, for ensuring a new instance of notepad++ for each call from Git.
Note also that, if you are using Git on Cygwin (and want to use Notepad++ from Cygwin), then scphantm explains in "using Notepad++ for Git inside Cygwin" that you must be aware that:
git is passing it a cyg...
Linux command or script counting duplicated lines in a text file?
...3
}
or you can use a simple one-liner:
$ cat filename | python3 -c 'print(__import__("json").dumps(__import__("collections").Counter(map(str.strip, __import__("fileinput").input())), indent=2))'
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Download multiple files with a single action
... don't portably parse multipart responses from the server side, but technically there's nothing difficult with doing this.
– CMCDragonkai
Jul 27 '18 at 4:25
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Why Choose Struct Over Class?
...es in many circumstances.
Structs are preferable if they are relatively small and copiable because copying is way safer than having multiple references to the same instance as happens with classes. This is especially important when passing around a variable to many classes and/or in a multithreaded...