大约有 40,000 项符合查询结果（耗时：0.0427秒） [XML]
MongoDB: Combine data from multiple collections into one..how?
..., reduce;
db.users_comments.remove();
// setup sample data - wouldn't actually use this in production
db.users.remove();
db.comments.remove();
db.users.save({firstName:"Rich",lastName:"S",gender:"M",country:"CA",age:"18"});
db.users.save({firstName:"Rob",lastName:"M",gender:"M",country:"US",age:"25...
Combining C++ and C - how does #ifdef __cplusplus work?
...f legacy C code. We've started writing in C++, with the intent to eventually convert the legacy code, as well. I'm a little confused about how the C and C++ interact. I understand that by wrapping the C code with extern "C" the C++ compiler will not mangle the C code's names, but I'm no...
Count character occurrences in a string in C++
...
Small note, but the return type is typically signed. For some reason std::count returns type iterator_traits<InputIt>::difference_type, which for most standard containers is std::ptrdiff_t, not std::size_t.
...
What exactly does Perl's “bless” do?
...to a hash (most common case), to an array (not so common), to a scalar (usually this indicates an inside-out object), to a regular expression, subroutine or TYPEGLOB (see the book Object Oriented Perl: A Comprehensive Guide to Concepts and Programming Techniques by Damian Conway for useful examples)...
Best way to create unique token in Rails?
...
Yeah, that's not bad. I'm usually looking for much shorter strings, to use as part of an URL.
– Slick23
Jan 3 '12 at 16:46
...
What does $_ mean in PowerShell?
...
This is the variable for the current value in the pipe line, which is called $PSItem in Powershell 3 and newer.
1,2,3 | %{ write-host $_ }
or
1,2,3 | %{ write-host $PSItem }
For example in the above code the %{} block is called for every value in the array. The $_ or $PSItem variable ...
Is there a standard way to list names of Python modules in a package?
Is there a straightforward way to list the names of all modules in a package, without using __all__ ?
10 Answers
...
How to make a class property? [duplicate]
...az.bar == 50
assert foo.bar == 50
The setter didn't work at the time we call Bar.bar, because we are calling
TypeOfBar.bar.__set__, which is not Bar.bar.__set__.
Adding a metaclass definition solves this:
class ClassPropertyMetaClass(type):
def __setattr__(self, key, value):
if key ...
Lightweight Javascript DB for use in Node.js [closed]
...with Persistence for node-webkit
LokiJS to be the ideal solution:
Mobile applications - especially HTML5 based (Cordova, Phonegap,
etc.)
Node.js embedded datastore for small-to-medium apps
Embedded in desktop application with Node Webkit
https://github.com/techfort/LokiJS
...
Why do we need extern “C”{ #include } in C++?
...
C and C++ are superficially similar, but each compiles into a very different set of code. When you include a header file with a C++ compiler, the compiler is expecting C++ code. If, however, it is a C header, then the compiler expects the data cont...