大约有 16,000 项符合查询结果（耗时：0.0300秒） [XML]
Set a default parameter value for a JavaScript function
...used if the value isn't defined (and ignored if the value is passed). In Ruby you can do it like this:
27 Answers
...
What's better at freeing memory with PHP: unset() or $var = null
... overhead of a function call ( update , is actually a language construct), but it would be interesting to know if one is better than the other. I have been using unset() for most of my coding, but I've recently looked through a few respectable classes found off the net that use $var = null inste...
How to change string into QString?
...
If by string you mean std::string you can do it with this method:
QString QString::fromStdString(const std::string & str)
std::string str = "Hello world";
QString qstr = QString::fromStdString(str);
If by string you mean Ascii...
UIBarButtonItem with custom image and no border
I want to create a UIBarButtonItem with a custom image, but I don't want the border that iPhone adds, as my Image has a special border.
...
How to get the body's content of an iframe in Javascript?
What I want to get is:
9 Answers
9
...
MySQL SELECT only not null values
...
You should use IS NOT NULL. (The comparison operators = and <> both give UNKNOWN with NULL on either side of the expression.)
SELECT *
FROM table
WHERE YourColumn IS NOT NULL;
Just for completeness I'll mention that in MySQL you can also negate the null safe equality operator bu...
How to use Python's pip to download and keep the zipped files for a package?
If I want to use the pip command to download a package (and its dependencies), but keep all of the zipped files that get downloaded (say, django-socialregistration.tar.gz) - is there a way to do that?
...
What is the Comonad typeclass in Haskell?
...es that provide a Comonad typeclass are also welcome). I've vaguely heard about Comonad, but all I really know about it is that is provides extract :: w a -> a , sort of a parallel to Monad's return :: a -> m a .
...
How do I create a foreign key in SQL Server?
I have never "hand-coded" object creation code for SQL Server and foreign key decleration is seemingly different between SQL Server and Postgres. Here is my sql so far:
...
Using Chrome, how to find to which events are bound to an element
Lets suppose I've a link on my page:
8 Answers
8
...