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What killed my process and why?
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answered Apr 7 '09 at 17:23
dwcdwc
20.8k55 gold badges3939 silver badges5252 bronze badges
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Why does ++[[]][+[]]+[+[]] return the string “10”?
This is valid and returns the string "10" in JavaScript ( more examples here ):
9 Answers
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What's the difference between tilde(~) and caret(^) in package.json?
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4053
See the NPM docs and semver docs:
~version “Approximately equivalent to version”, will up...
C char array initialization
... how you initialize an array, but for:
The first declaration:
char buf[10] = "";
is equivalent to
char buf[10] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
The second declaration:
char buf[10] = " ";
is equivalent to
char buf[10] = {' ', 0, 0, 0, 0, 0, 0, 0, 0, 0};
The third declaration:
char buf[...
Fastest way to determine if an integer's square root is an integer
...ts. (I found looking at the last six didn't help.) I also answer yes for 0. (In reading the code below, note that my input is int64 x.)
if( x < 0 || (x&2) || ((x & 7) == 5) || ((x & 11) == 8) )
return false;
if( x == 0 )
return true;
Next, check if it's a square modulo 25...
What is the most pythonic way to check if an object is a number?
...cimal import Decimal
... from fractions import Fraction
... for n in [2, 2.0, Decimal('2.0'), complex(2, 0), Fraction(2, 1), '2']:
... print(f'{n!r:>14} {isinstance(n, Number)}')
2 True
2.0 True
Decimal('2.0') True
(2+0j) True
Fraction(2, 1) True
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Most efficient way to create a zero filled JavaScript array?
...duces Array.prototype.fill. It can be used like this:
new Array(len).fill(0);
Not sure if it's fast, but I like it because it's short and self-describing.
It's still not in IE (check compatibility), but there's a polyfill available.
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How to validate an e-mail address in swift?
...ValidEmail(_ email: String) -> Bool {
let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"
let emailPred = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
return emailPred.evaluate(with: email)
}
for versions of Swift earlier than 3.0:
func isValidEmail(e...
How to detect if a script is being sourced
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This seems to be portable between Bash and Korn:
[[ $_ != $0 ]] && echo "Script is being sourced" || echo "Script is a subshell"
A line similar to this or an assignment like pathname="$_" (with a later test and action) must be on the first line of the script or on the line ...
How can I check if an ip is in a network in Python?
Given an ip address (say 192.168.0.1), how do I check if it's in a network (say 192.168.0.0/24) in Python?
27 Answers
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