大约有 40,000 项符合查询结果（耗时：0.0614秒） [XML]
What's the best practice for primary keys in tables?
...ary. Prefer a numeric type because numeric types are stored in a much more compact format than character formats. This is because most primary keys will be foreign keys in another table as well as used in multiple indexes. The smaller your key, the smaller the index, the less pages in the cache you ...
What does a tilde do when it precedes an expression?
... 0000 0000 0000 0001
If it were a negative number, it'd be stored in 2's complement: invert all bits and add 1.
...and then flips all its bits...
1111 1111 1111 1111 1111 1111 1111 1110
So what is the use of it, then? When might one ever use it?
It has a quite a few uses. If you're writin...
Why prefer two's complement over sign-and-magnitude for signed numbers?
I'm just curious if there's a reason why in order to represent -1 in binary, two's complement is used: flipping the bits and adding 1?
...
Is there a common Java utility to break a list into batches?
...atches of given size. I just wanted to know if there is already any apache commons util for this.
17 Answers
...
Python __call__ special method practical example
...
add a comment
|
121
...
Is gcc's __attribute__((packed)) / #pragma pack unsafe?
In C, the compiler will lay out members of a struct in the order in which they're declared, with possible padding bytes inserted between members, or after the last member, to ensure that each member is aligned properly.
...
C# 能否获取一个对象所占内存的大小？ - 更多技术 - 清泛网 - 专注C/C++及内核技术
...null ConsoleApplication3.Student
延伸阅读： http://blogs.msdn.com/b/cbrumme/archive/2003/04/15/51326.aspx
原文如下：
We don't expose the managed size of objects because we want to reserve the ability to change the way we lay these things out. For example, on some systems we migh...
Computed read-only property vs function in Swift
...ons (or methods) when actual work is being done. Maybe something has to be computed or read from disk or from a database: In this case I use a function, even when only a simple value is returned. That way I can easily see whether a call is cheap (properties) or possibly expensive (functions).
We w...
Trying to login to RDP using AS3
I am trying to login to RDP using AS3 (air). I am doing ok, considering the lack of resources out there to understand the actual process.
...
Error while installing json gem 'mkmf.rb can't find header files for ruby'
...is no ruby development environment installed. Development env is needed to compile ruby extensions, which are mostly written in C. Proxy has nothing to do with the problem: everything is downloaded fine, just compilation fails.
I would suggest you to install ruby-dev (ruby-devel for rpm-based distr...