大约有 40,000 项符合查询结果（耗时：0.0582秒） [XML]
What is a regular expression for a MAC Address?
... As an aside, the quote above concerning "standard format" comes from Wikipedia, not the 802.3 standards body. IEEE 802-2014 actually specifies hyphens for ordinary MAC addresses (§ 8.1 ¶ 3) and colons for the obsolescent bit-reversed notation (¶ 4). Importantly, in practice, no one o...
What is Cache-Control: private?
...e in the same 15-second window will all get the same contents - all served from close cache. Performance win for everyone.
The virtue of adding Cache-Control: max-age is that the browser doesn't even have to perform a conditional request.
if you specified only Last-Modified, the browser has to pe...
If strings are immutable in .NET, then why does Substring take O(n) time?
...(n) is O(1) if n does not grow large. Most people extract tiny substrings from tiny strings, so how the complexity grows asymptotically is completely irrelevant.
The long answer is:
An immutable data structure built such that operations on an instance permit re-use of the memory of the original w...
Scatterplot with marginal histograms in ggplot2
...
You're right. They're sampled from the same distribution though, so the marginal histograms should theoretically match the scatter plot.
– oeo4b
Dec 17 '11 at 17:03
...
AngularJS : How to watch service variables?
...e/unkown objects might be interested in changes, use $rootScope.$broadcast from the item being changed.
Rather than creating your own registry of listeners (which have to be cleaned up on various $destroys), you should be able to $broadcast from the service in question.
You must still code the $...
Where to use EJB 3.1 and CDI?
...bean. The @Stateless is basically an instance pool -- you get an instance from the pool for the duration of one invocation. The @Singleton is essentially @ApplicationScoped
So in a fundamental level, anything you can do with an "EJB" bean you should be able to do with a "CDI" bean. Under the cov...
Lambda function in list comprehensions
...ion.
I don't think the purpose of the OP was to generate a list of squares from 0 to 9. If that was the case, we could give even more solutions:
squares = []
for x in range(10): squares.append(x*x)
this is the good ol' way of imperative syntax.
But it's not the point. The point is W(hy)TF is this...
Difference between filter and filter_by in SQLAlchemy
... db.users.name=='Ryan' evaluate once to a constant and then be meaningless from then on? It seems like one would need to use a lambda for this to work.
– Hamish Grubijan
Feb 27 '13 at 23:11
...
How do I seed a random class to avoid getting duplicate random values [duplicate]
...andom numbers. Of course, in this case, the generated sequence will be far from uniform distribution.
For the sake of completeness, if you really need to reseed a Random, you'll create a new instance of Random with the new seed:
rnd = new Random(newSeed);
...
Should I use Java date and time classes or go with a 3rd party library like Joda Time?
I'm creating a web based system which will be used in countries from all over the world. One type of data which must be stored is dates and times.
...