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is_null($x) vs $x === null in PHP [duplicate]
...someone strongly suggested that I use is_null() instead as it is specifically designed for the null-evaluation purpose. He also started talking about math or something.
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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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Read url to string in few lines of java code
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Just don't forget you need to call Scanner#close() later.
– Marcelo
Dec 21 '12 at 3:55
2
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Difference between del, remove and pop on lists
...gt;>> a = [4, 5, 6]
>>> a.remove(7)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: list.remove(x): x not in list
>>> del a[7]
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
IndexError: lis...
Nested defaultdict of defaultdict
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For an arbitrary number of levels:
def rec_dd():
return defaultdict(rec_dd)
>>> x = rec_dd()
>>> x['a']['b']['c']['d']
defaultdict(<function rec_dd at 0x7f0dcef81500>, {})
>>> print json.dumps(x)
{"a": {"b": {"c": {"d": {}}}}}
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Numpy first occurrence of value greater than existing value
... about why it gives the correct result despite the original intent not actually seeking a maximum, not why it is faster as I cannot claim to understand the inner details of argmax.
– askewchan
Oct 8 '14 at 14:24
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How to resolve “must be an instance of string, string given” prior to PHP 7?
... supposed to work to begin with. Given the dynamic typing system, this actually makes some sort of perverted sense.
You can only manually "type hint" scalar types:
function foo($string) {
if (!is_string($string)) {
trigger_error('No, you fool!');
return;
}
...
}
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Fast way of counting non-zero bits in positive integer
...nt() took about 1/20th of the time of bin(n).count("1"). So if you can install gmpy, use that.
To answer a question in the comments, for bytes I'd use a lookup table. You can generate it at runtime:
counts = bytes(bin(x).count("1") for x in range(256)) # py2: use bytearray
Or just define it lit...
How to find where gem files are installed
I can finds gems that are installed using gem list , but it doesn't show me where the gems are installed.
10 Answers
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How do I send a POST request with PHP?
Actually I want to read the contents that come after the search query, when it is done. The problem is that the URL only accepts POST methods, and it does not take any action with GET method...
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