大约有 42,000 项符合查询结果（耗时：0.0649秒） [XML]
What does “atomic” mean in programming?
... written using two separate operations: one that writes the first 32 bits, and a second one which writes the last 32 bits. That means that another thread might read the value of foo, and see the intermediate state.
Making the operation atomic consists in using synchronization mechanisms in order t...
NSString tokenize in Objective-C
...red Nov 3 '08 at 21:10
Adam AlexanderAdam Alexander
14.9k55 gold badges3838 silver badges4141 bronze badges
...
Flatten an irregular list of lists
...
Using generator functions can make your example a little easier to read and probably boost the performance.
Python 2
def flatten(l):
for el in l:
if isinstance(el, collections.Iterable) and not isinstance(el, basestring):
for sub in flatten(el):
yield sub...
“You have mail” message in terminal, os X [closed]
...ably it is some message from your system.
Type in terminal:
man mail
, and see how can you get this message from your system.
share
|
improve this answer
|
follow
...
jQuery get textarea text
Recently I have started playing with jQuery, and have been following a couple of tutorials. Now I feel slightly competent with using it (it's pretty easy), and I thought it would be cool if I were able to make a 'console' on my webpage (as in, you press the ` key like you do in FPS games, etc.), a...
simulate background-size:cover on or
...r a while, but I came across a great solution that doesn't use any script, and can achieve a perfect cover simulation on video with 5 lines of CSS (9 if you count selectors and brackets). This has 0 edge-cases in which it doesn't work perfectly, short of CSS3-compatibility.
You can see an example h...
Should an Enum start with a 0 or a 1?
...ag enum values of zero unless the value represents "all flags are cleared" and is named appropriately, as prescribed by the next guideline.
✔️ DO name the zero value of flag enums None. For a flag enum, the value must always mean "all flags are cleared."
...
Python unittest - opposite of assertRaises?
...r test must exit with a failure condition, not an error one. On the other hand, if in running the same code you would raise a KeyError, that would be an error, not a failure. In python - differently than some other languages - Exceptions are routinely used for control flow, this is why we have the e...
Where does R store packages?
...all.packages() function in R is the automatic unzipping utility that gets and install packages in R.
4 Answers
...
How do negative margins in CSS work and why is (margin-top:-5 != margin-bottom:5)?
...
Negative margins are valid in css and understanding their (compliant) behaviour is mainly based on the box model and margin collapsing. While certain scenarios are more complex, a lot of common mistakes can be avoided after studying the spec.
For instance, r...