大约有 48,000 项符合查询结果（耗时：0.1051秒） [XML]
What is the difference between the remap, noremap, nnoremap and vnoremap mapping commands in Vim?
...ajority of use cases, but it should be noted that :map, etc. don't work in all modes, exactly, just all the common ones (specifically, normal mode, visual mode, select mode, and operator-pending mode). If you want a mapping to work in insert, command-line, or lang-arg mode, you need to use :map!, et...
SQL Server Management Studio won't let me add an index to a table
... "New Index" menu item is grayed out. I don't understand why. I've deleted all data in the table just in case, and refreshed and restarted SSMS, but no luck. I'm using SQL Server 2012 Business Intelligence SP1 CTP.
...
What is the best way to test for an empty string in Go?
... one that makes the code clear.
If I'm about to look at element x I typically write
len(s) > x, even for x == 0, but if I care about
"is it this specific string" I tend to write s == "".
It's reasonable to assume that a mature compiler will compile
len(s) == 0 and s == "" into the ...
C# nullable string error
...
For nullable, use ? with all of the C# primitives, except for string.
The following page gives a list of the C# primitives:
http://msdn.microsoft.com/en-us/library/aa711900(v=vs.71).aspx
...
Which one will execute faster, if (flag==0) or if (0==flag)?
...n :)
The answer is:
What is flag's type?
In the case where flag actually is a user-defined type. Then it depends on which overload of operator== is selected. Of course it can seem stupid that they would not be symmetric, but it's certainly allowed, and I have seen other abuses already.
If fl...
Why isn't there a Guid.IsNullOrEmpty() method
...why Guid in .NET does not have IsNullOrEmpty() method (where empty means all zeros)
6 Answers
...
Why does the arrow (->) operator in C exist?
...as two questions: 1) why -> even exists, and 2) why . does not automatically dereference the pointer. Answers to both questions have historical roots.
Why does -> even exist?
In one of the very first versions of C language (which I will refer as CRM for "C Reference Manual", which came with ...
What is the difference between Bower and npm?
...
All package managers have many downsides. You just have to pick which you can live with.
History
npm started out managing node.js modules (that's why packages go into node_modules by default), but it works for the front-end...
Get most recent file in a directory on Linux
...
A minor issue: This version pipes all the output of ls to tail, then prints only the LAST line. IMHO it is better to sort in ascending order and use head instead, as chaos suggested. After printing the first line head quits, so sending the next line (actually...
Can you make just part of a regex case-insensitive?
...ase-insensitive by using the (?i:) pattern modifier.
Modern regex flavors allow you to apply modifiers to only part of the regular expression. If you insert the modifier (?ism) in the middle of the regex, the modifier only applies to the part of the regex to the right of the modifier. You can turn ...