大约有 46,000 项符合查询结果（耗时：0.0905秒） [XML]
Instance variable: self vs @
...ng self.age tells the object to send itself the message age, which will usually return the instance variable @age — but could do any number of other things depending on how the age method is implemented in a given subclass. For example, you might have a MiddleAgedSocialite class that always report...
Is HTML5 localStorage asynchronous?
...
Nope, all localStorage calls are synchronous.
share
|
improve this answer
|
follow
|
...
Append an object to a list in R in amortized constant time, O(1)?
...irthday. Some kind readers keep repeating any shortcomings with it, so by all means also see some of the comments below. One suggestion for list types:
newlist <- list(oldlist, list(someobj))
In general, R types can make it hard to have one and just one idiom for all types and uses.
...
How to import multiple .csv files at once?
...ariables but each from different times.
Is there a way in R to import them all simultaneously rather than having to import them all individually?
...
Is False == 0 and True == 1 an implementation detail or is it guaranteed by the language?
.....] Boolean values behave like the values 0 and 1, respectively, in almost all contexts, the exception being that when converted to a string, the strings "False" or "True" are returned, respectively.
There is also, for Python 2:
In numeric contexts (for example when used as the argument to an ...
HTTP Content-Type Header and JSON
...n't care what it is. The browser just returns you the data from the AJAX call. If you want to parse it as JSON, you need to do that on your own.
The header is there so your app can detect what data was returned and how it should handle it. You need to look at the header, and if it's application/...
What Makes a Method Thread-safe? What are the rules?
Are there overall rules/guidelines for what makes a method thread-safe? I understand that there are probably a million one-off situations, but what about in general? Is it this simple?
...
Maven: Command to update repository after adding dependency to POM
...
mvn install (or mvn package) will always work.
You can use mvn compile to download compile time dependencies or mvn test for compile time and test dependencies but I prefer something that always works.
...
How to read the mode field of git-ls-tree's output
...ing 0 on the top lines (e.g. 0170000 instead of 170000), since it is 0 for all lines, why not just omit it?
– Ciro Santilli 郝海东冠状病六四事件法轮功
Aug 22 '14 at 7:47
...
Is there a timeout for idle PostgreSQL connections?
...th <idle> in transaction sessions, but with too many connections overall.
Killing connections is not the right answer for that, but it's an OK-ish temporary workaround.
Rather than re-starting PostgreSQL to boot all other connections off a PostgreSQL database, see: How do I detach all other ...