大约有 47,000 项符合查询结果（耗时：0.0348秒） [XML]
Can someone explain this 'double negative' trick? [duplicate]
...ue.
The "falsey" values are:
false
NaN
undefined
null
"" (empty string)
0
share
|
improve this answer
|
follow
|
...
How to extract text from a string using sed?
...
The pattern \d might not be supported by your sed. Try [0-9] or [[:digit:]] instead.
To only print the actual match (not the entire matching line), use a substitution.
sed -n 's/.*\([0-9][0-9]*G[0-9][0-9]*\).*/\1/p'
...
How to debug a GLSL shader?
...
answered Mar 24 '10 at 17:14
Mr. BernaMr. Berna
10.1k11 gold badge3737 silver badges4141 bronze badges
...
Remove a string from the beginning of a string
...gex:
$prefix = 'bla_';
$str = 'bla_string_bla_bla_bla';
if (substr($str, 0, strlen($prefix)) == $prefix) {
$str = substr($str, strlen($prefix));
}
Takes: 0.0369 ms (0.000,036,954 seconds)
And with:
$prefix = 'bla_';
$str = 'bla_string_bla_bla_bla';
$str = preg_replace('/^' . preg_quote($p...
Fastest way to flatten / un-flatten nested JSON objects
...
+500
Here's my much shorter implementation:
Object.unflatten = function(data) {
"use strict";
if (Object(data) !== data || Array....
Maintain aspect ratio of div but fill screen width and height in CSS?
... breaking the ratio and without scrollbars!
(PURE) CSS
div
{
width: 100vw;
height: 56.25vw; /* height:width ratio = 9/16 = .5625 */
background: pink;
max-height: 100vh;
max-width: 177.78vh; /* 16/9 = 1.778 */
margin: auto;
position: absolute;
top:0;bottom:0; /* ve...
How can I eliminate slow resolving/loading of localhost/virtualhost (a 2-3 second lag) on Mac OS X L
...environments on Mac OS X Lion (brand new macbook air purchased in January 2012), I have noticed that resolving to a virtual host is very slow (around 3 seconds) the first time but after that is fast as long as I continue loading it regularly.
...
SVG gradient using CSS
...pe-rendering: crispEdges;
fill: url(#MyGradient);
}
<svg width="100" height="50" version="1.1" xmlns="http://www.w3.org/2000/svg">
<style type="text/css">
rect{fill:url(#MyGradient)}
</style>
<defs>
<linearGradient id="MyGradie...
Is 0 a decimal literal or an octal literal?
...hat actually almost all integer literals in my code are octal, namely 0 .
3 Answers
...
What is “2's Complement”?
...e to think of the numbers in binary.
It basically says,
for zero, use all 0's.
for positive integers, start counting up, with a maximum of 2(number of bits - 1)-1.
for negative integers, do exactly the same thing, but switch the role of 0's and 1's (so instead of starting with 0000, start with 1111...