大约有 47,000 项符合查询结果（耗时：0.0685秒） [XML]
Get a specific bit from byte
...
Easy. Use a bitwise AND to compare your number with the value 2^bitNumber, which can be cheaply calculated by bit-shifting.
//your black magic
var bit = (b & (1 << bitNumber-1)) != 0;
EDIT: To add a little more detail because there ...
What exactly is a C pointer if not a memory address?
...
The C standard does not define what a pointer is internally and how it works internally. This is intentional so as not to limit the number of platforms, where C can be implemented as a compiled or interpreted language.
A pointer val...
Reference: mod_rewrite, URL rewriting and “pretty links” explained
...plained. mod_rewrite is one way to make "pretty links", but it's complex and its syntax is very terse, hard to grok, and the documentation assumes a certain level of proficiency in HTTP. Can someone explain in simple terms how "pretty links" work and how mod_rewrite can be used to create them?
...
What is the usefulness of PUT and DELETE HTTP request methods?
... origin server. If the Request-URI does not point to an existing resource, and that URI is capable of being defined as a new resource by the requesting user agent, the origin server can create the resource with that URI …
For the full specification visit:
http://www.w3.org/Protocols/rfc2616/rf...
Approximate cost to access various caches and main memory?
Can anyone give me the approximate time (in nanoseconds) to access L1, L2 and L3 caches, as well as main memory on Intel i7 processors?
...
Repeat String - Javascript
...
Note to new readers: This answer is old and and not terribly practical - it's just "clever" because it uses Array stuff to get
String things done. When I wrote "less process" I definitely meant
"less code" because, as others have noted in subsequent answers, it...
Understanding recursion [closed]
I'm having major trouble understanding recursion at school. Whenever the professor is talking about it, I seem to get it but as soon as I try it on my own it completely blows my brains.
...
Why does Date.parse give incorrect results?
...In the 5th edition spec the requirement was added to support a simplified (and slightly incorrect) ISO-8601 (also see What are valid Date Time Strings in JavaScript?). But other than that, there was no requirement for what Date.parse / new Date(string) should accept other than that they had to accep...
Fundamental difference between Hashing and Encryption algorithms
I see a lot of confusion between hashes and encryption algorithms and I would like to hear some more expert advice about:
1...
What do all of Scala's symbolic operators mean?
...e method defined on List (though it could be the object of the same name), and :+= is probably the method defined on various Buffer classes.
So, let's see them.
Keywords/reserved symbols
There are some symbols in Scala that are special. Two of them are considered proper keywords, while others are...