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How does database indexing work? [closed]
...d on it."
– grinch
Nov 12 '14 at 20:32
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show 29 more comments
...
Applying a function to every row of a table using dplyr?
...function(x) 1:5, .collate = "cols")
produces, respectively:
# A tibble: 32 × 3
mpg cyl .out
<dbl> <dbl> <list>
1 21.0 6 <int [5]>
2 21.0 6 <int [5]>
3 22.8 4 <int [5]>
4 21.4 6 <int [5]>
5 18.7 8 <int [5...
“is” operator behaves unexpectedly with integers
...ency
In [29]: a = 3
In [30]: b = 3
In [31]: id(a)
Out[31]: 500729144
In [32]: id(b)
Out[32]: 500729144
You should use == to compare equality of arbitrary objects. You can specify the behavior with the __eq__, and __ne__ attributes.
...
What to do Regular expression pattern doesn't match anywhere in string?
...he subject (possibly best SO answer period): stackoverflow.com/questions/1732348/…
– Daniel Ribeiro
Jul 8 '11 at 14:29
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show 12 more comm...
How to parse an RSS feed using JavaScript?
...swered Oct 2 '19 at 10:57
Ukuser32Ukuser32
1,80122 gold badges1515 silver badges3030 bronze badges
...
What is the difference between RDF and OWL? [closed]
...
32
RDF, RDFS and OWL are means to express increasingly complex information or knowledge. All of th...
Difference between DateTime and Time in Ruby
...In versions prior to Ruby 1.9 and on many systems Time is represented as a 32-bit signed value describing the number of seconds since January 1, 1970 UTC, a thin wrapper around a POSIX-standard time_t value, and is bounded:
Time.at(0x7FFFFFFF)
# => Mon Jan 18 22:14:07 -0500 2038
Time.at(-0x7FFFF...
How do I use reflection to call a generic method?
...blic.
– user565869
Dec 16 '11 at 22:32
20
The correct combination of flags is BindingFlags.NonPub...
How do you Encrypt and Decrypt a PHP String?
...) {
throw new RangeException('Key is not the correct size (must be 32 bytes).');
}
$nonce = random_bytes(SODIUM_CRYPTO_SECRETBOX_NONCEBYTES);
$cipher = base64_encode(
$nonce.
sodium_crypto_secretbox(
$message,
$nonce,
$key
...
What is an IndexOutOfRangeException / ArgumentOutOfRangeException and how do I fix it?
...id test() {
// This will throw InvalidCastException, cannot convert Int32[] to Int32[*]
foo((int)Array.CreateInstance(typeof(int), new int[] { 1 }, new int[] { 1 }));
}
Validate Parameters
If index comes from a parameter you should always validate them (throwing appropriate ArgumentExcepti...