大约有 7,000 项符合查询结果（耗时：0.0231秒） [XML]
What's with 181783497276652981 and 8682522807148012 in Random (Java 7)?
...ses a multiplicative linear congruential generator (MLCG) with c=0 and m=2^64. (The modulus 2^64 is implicitly given by the overflow of 64bit long integers)
Because of the zero c and the power-of-2-modulus, the "quality" (cycle length, bit-correlation, ...) is limited. As the paper says, besides the...
How to validate an e-mail address in swift?
...
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(email: String) -> Bool {
let emailRe...
How to convert an IPv4 address into a integer in C#?
...ses. Meanwhile, the IPAddress.Address property, while deprecated, is an Int64 that returns the unsigned 32-bit value of the IPv4 address (the catch is, it's in network byte order, so you need to swap it around).
For example, my local google.com is at 64.233.187.99. That's equivalent to:
64*2^24 + ...
Maximum length for MySQL type text
... (255 Bytes)
BLOB, TEXT L + 2 bytes, where L < 2^16 (64 Kilobytes)
MEDIUMBLOB, MEDIUMTEXT L + 3 bytes, where L < 2^24 (16 Megabytes)
LONGBLOB, LONGTEXT L + 4 bytes, where L < 2^32 (4 Gigabytes)
L is the number of bytes in your text field. So the maximum numb...
What is the best way to repeatedly execute a function every x seconds?
...nd have it run every second without delay...
– Angry 84
Jan 1 '16 at 22:48
7
I prefer from time i...
What does numpy.random.seed(0) do?
...([ 0.42, 0.65, 0.44, 0.89])
>>> numpy.random.rand(4)
array([ 0.96, 0.38, 0.79, 0.53])
(pseudo-)random numbers work by starting with a number (the seed), multiplying it by a large number, adding an offset, then taking modulo of that sum. The resulting number is then used as the seed...
C# Lambda expressions: Why should I use them?
...
84
I found them useful in a situation when I wanted to declare a handler for some control's event,...
What is causing “Unable to allocate memory for pool” in PHP?
...allowing only 32MB is ridiculously low. PHP was designed when servers were 64MB and most scripts were using one php file per page. Nowadays solutions like Magento require more than 10k files (~60Mb in APC). You should allow enough memory so most of php files are always cached. It's not a waste, it's...
Why does += behave unexpectedly on lists?
...
96
For the general case, see Scott Griffith's answer. When dealing with lists like you are, though...
float64 with pandas to_csv
...tp://www.w3.org/2000/svg\"\u003e\u003cpath d=\"M46.1709 9.17788C46.1709 8.26454 46.2665 7.94324 47.1084 7.58816C47.4091 7.46349 47.7169 7.36433 48.0099 7.26993C48.9099 6.97997 49.672 6.73443 49.672 5.93063C49.672 5.22043 48.9832 4.61182 48.1414 4.61182C47.4335 4.61182 46.7256 4.91628 46.0943 5.50789...