大约有 47,000 项符合查询结果（耗时：0.0319秒） [XML]
Use cases for the 'setdefault' dict method
...e case: Grouping items (in unsorted data, else use itertools.groupby)
# really verbose
new = {}
for (key, value) in data:
if key in new:
new[key].append( value )
else:
new[key] = [value]
# easy with setdefault
new = {}
for (key, value) in data:
group = new.setdefault(k...
How do you build a Singleton in Dart?
... There's the weird syntax Singleton._internal(); that looks like a method call when it's really a constructor definition. There's the _internal name. And there's the nifty language design point that Dart lets you start out (dart out?) using an ordinary constructor and then, if needed, change it to a...
How to avoid “if” chains?
...ep<X>() should evaluate only if the previous one succeeded (this is called short circuit evaluation)
executeThisFunctionInAnyCase() will be executed in any case
share
|
improve this answer
...
Underscore prefix for property and method names in JavaScript
...
Welcome to 2019!
It appears a proposal to extend class syntax to allow for # prefixed variable to be private was accepted. Chrome 74 ships with this support.
_ prefixed variable names are considered private by convention but are still public.
This syntax tries to be both terse and int...
How to calculate the difference between two dates using PHP?
...ferred way of doing this is like described by jurka below. My code is generally only recommended if you don't have PHP 5.3 or better.
Several people in the comments have pointed out that the code above is only an approximation. I still believe that for most purposes that's fine, since the usage of...
How to enable C++11/C++0x support in Eclipse CDT?
..., find the Preprocessor Include Path and go to the Providers Tab. Deselect all except CDT GCC Builtin Compiler Settings. Then untag Share settings entries … . Add the option -std=c++11 to the text box called Command to get compiler specs.
Go to paths and symbols. Under Symbols, click restore defau...
What is the meaning of “__attribute__((packed, aligned(4))) ”
...gned(1))) sSampleStruct;
so the above specified gcc attribute does not allow the structure padding. so the size will be 8 bytes.
If you wish to do the same for all the structures, simply we can push the alignment value to stack using #pragma
#pragma pack(push, 1)
//Structure 1
......
//Stru...
Why shouldn't I use mysql_* functions in PHP?
...
The MySQL extension:
Is not under active development
Is officially deprecated as of PHP 5.5 (released June 2013).
Has been removed entirely as of PHP 7.0 (released December 2015)
This means that as of 31 Dec 2018 it does not exist in any supported version of PHP. If you are using a ve...
lodash multi-column sortBy descending
...dash.com/docs#orderBy) in Lodash as of 4.3.0. The normal sort function is called _.sortBy(lodash.com/docs#sortBy)
– Nidhin David
Feb 12 '16 at 11:19
2
...
Semantic Issue: Property's synthesized getter follows Cocoa naming convention for returning 'owned'
... the memory management rules for declared properties, too — more specifically, for declared properties’ accessors:
You take ownership of an object if you create it using a method whose name begins with “alloc”, “new”, “copy”, or “mutableCopy”.
A property named newTitle, whe...