大约有 46,000 项符合查询结果（耗时：0.0730秒） [XML]
What's quicker and better to determine if an array key exists in PHP?
...
isset() is faster, but it's not the same as array_key_exists().
array_key_exists() purely checks if the key exists, even if the value is NULL.
Whereas
isset() will return false if the key exist and value is NULL.
...
How to force garbage collection in Java?
Is it possible to force garbage collection in Java, even if it is tricky to do? I know about System.gc(); and Runtime.gc(); but they only suggest to do GC. How can I force GC?
...
I need to securely store a username and password in Python, what are my options?
I'm writing a small Python script which will periodically pull information from a 3rd party service using a username and password combo. I don't need to create something that is 100% bulletproof (does 100% even exist?), but I would like to involve a good measure of security so at the very least it w...
What is object slicing?
Someone mentioned it in the IRC as the slicing problem.
18 Answers
18
...
How do I tokenize a string in C++?
Java has a convenient split method:
35 Answers
35
...
When should we call System.exit in Java
In Java, What is the difference with or without System.exit(0) in following code?
10 Answers
...
What is the purpose of Serialization in Java?
I have read quite a number of articles on Serialization and how it is so nice and great but none of the arguments were convincing enough. I am wondering if someone can really tell me what is it that we can really achieve by serializing a class?
...
Why does integer overflow on x86 with GCC cause an infinite loop?
The following code goes into an infinite loop on GCC:
6 Answers
6
...
Why are variables “i” and “j” used for counters?
...
It comes ultimately from mathematics: the summation notation traditionally uses i for the first index, j for the second, and so on. Example (from http://en.wikipedia.org/wiki/Summation):
It's also used that way for co...
How to deal with a slow SecureRandom generator?
...you use SecureRandom . Unfortunately, SecureRandom can be very slow. If it uses /dev/random on Linux, it can block waiting for sufficient entropy to build up. How do you avoid the performance penalty?
...