大约有 2,253 项符合查询结果（耗时：0.0320秒） [XML]
Why is sizeof considered an operator?
...fine. They're often seen, firstly because they're needed as part of a type cast expression, and secondly because sizeof has very high precedence, so sizeof a + b isn't the same as sizeof (a+b). But they aren't part of the invocation of sizeof, they're part of the operand.
You can't take the address ...
Is null check needed before calling instanceof?
...lue of the RelationalExpression is
not null and the reference could be
cast to the ReferenceType
without raising a ClassCastException.
Otherwise the result is false."
So if the operand is null, the result is false.
...
How to get the error message from the error code returned by GetLastError()?
... pointer? But passing it the pointer's address (pointer-to-a-pointer), but casting it to a regular pointer... Win32 weirdness. Thanks for the heads up, fixed it in my own code base (and my answer). Very subtle catch.
– Jamin Grey
Jan 11 '14 at 1:45
...
Is there a Python equivalent to Ruby's string interpolation?
...
@Caste see here: docs.python.org/library/stdtypes.html#string-formatting and post a follow up comment if you need any more details
– mikej
Dec 15 '10 at 13:59
...
How to use performSelector:withObject:afterDelay: with primitive types in Cocoa?
...trick if it is a BOOL parameter.
Pass nil for NO and self for YES. nil is cast to the BOOL value of NO. self is cast to the BOOL value of YES.
This approach breaks down if it is anything other than a BOOL parameter.
Assuming self is a UIView.
//nil will be cast to NO when the selector is perform...
Passing a single item as IEnumerable
...f you pass in a list or an array, then an unscrupulous piece of code could cast it and change the contents, leading to odd behaviour in some situations. You could use a read-only collection, but that's likely to involve even more wrapping. I think your solution is as neat as it gets.
...
SQL Data Reader - handling Null column values
...sqlreader[indexAge] as int? ?? default(int);
The as operator handles the casting including the check for DBNull.
share
|
improve this answer
|
follow
|
...
How do I enumerate through a JObject?
...asons I don't understand, you can't use it with Linq unless you explicitly cast to the enumerable type. I.e. you ((IEnumerable<KeyValuePair<string, JToken>>)obj).Select(...) instead of plain-old obj.Select(...); or at least that's what I found it one part of my code.
...
[A]System.Web.WebPages.Razor.Configuration.HostSection cannot be cast to… web.config issue
I am getting the following error:
6 Answers
6
...
Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '=
...s not suffer of performance issues.
Using Option 1 and 2, aka the COLLATE cast approach, can lead to potential bottleneck, cause any index defined on the column will not be used causing a full scan.
Even though I did not try out Option 3, my hunch is that it will suffer the same consequences of op...