大约有 48,000 项符合查询结果（耗时：0.0573秒） [XML]
What exactly does an #if 0 … #endif block do?
...not get executed, it doesn't even get compiled.
#if is a preprocessor command, which gets evaluated before the actual compilation step. The code inside that block doesn't appear in the compiled binary.
It's often used for temporarily removing segments of code with the intention of turning them bac...
JSON serialization of Google App Engine models
...
A simple recursive function can be used to convert an entity (and any referents) to a nested dictionary that can be passed to simplejson:
import datetime
import time
SIMPLE_TYPES = (int, long, float, bool, dict, basestring, list)
def to_dict(model):
output = {}
for key, prop...
#ifdef in C#
...defined");
#elif (DEBUG && VC_V7)
Console.WriteLine("DEBUG and VC_V7 are defined");
#else
Console.WriteLine("DEBUG and VC_V7 are not defined");
#endif
}
}
Only useful for excluding parts of methods.
If you use #if to exclude some method from compilation then you will h...
What should be in my .gitignore for an Android Studio project?
What files should be in my .gitignore for an Android Studio project?
31 Answers
31
...
Why does this code segfault on 64-bit architecture but work fine on 32-bit?
...has an entry discussing why casting the return from malloc is never needed and potentially bad.
share
|
improve this answer
|
follow
|
...
Map implementation with duplicate keys
...
You are searching for a multimap, and indeed both commons-collections and Guava have several implementations for that. Multimaps allow for multiple keys by maintaining a collection of values per key, i.e. you can put a single object into the map, but you retr...
getting the last item in a javascript object
...
No. Order is not guaranteed in JSON and most other key-value data structures, so therefore the last item could sometimes be carrot and at other times be banana and so on. If you need to rely on ordering, your best bet is to go with arrays. The power of key-val...
Python extending with - using super() Python 3 vs Python 2
... super(__class__) gives NameError: global name '__class__' is not defined, and super(self.__class__) is erroneous as well. You must provide an instance as a second argument, which would suggest you need to do super(self.__class__, self), but that is wrong. If Class2 inherits from Class1 and Class1 c...
What is the difference between the hidden attribute (HTML5) and the display:none rule (CSS)?
...rtaain cases you don't want it to be a part of the visual experience then handle it at the cosmetic layer. Bear in mind that some agents attempt to parse CSS and if they determine that something wouldn't be SEEN then they don't output it at all. I think this is aberrant behavior but it can help to k...
Why does Java switch on contiguous ints appear to run faster with added cases?
... (bytecode instruction tableswitch).
However, once the JIT starts its job and compiles the bytecode into assembly, the tableswitch instruction does not always result in an array of pointers: sometimes the switch table is transformed into what looks like a lookupswitch (similar to an if/else if stru...