大约有 41,000 项符合查询结果（耗时：0.0155秒） [XML]
Why should casting be avoided? [closed]
I generally avoid casting types as much as possible since I am under the impression that it's poor coding practice and may incur a performance penalty.
...
TSQL - Cast string to integer or return default value
Is there a way in T-SQL to cast an nvarchar to int and return a default value or NULL if the conversion fails?
8 Answers
...
When to use Cast() and Oftype() in Linq
I am aware of two methods of casting types to IEnumerable from an Arraylist in Linq and wondering in which cases to use them?
...
How do I check to see if a value is an integer in MySQL?
I see that within MySQL there are Cast() and Convert() functions to create integers from values, but is there any way to check to see if a value is an integer? Something like is_int() in PHP is what I am looking for.
...
How to cast int to enum in C++?
How do I cast an int to an enum in C++?
5 Answers
5
...
Difference between is and as keyword
...
is
The is operator checks if an object can be cast to a specific type.
Example:
if (someObject is StringBuilder) ...
as
The as operator attempts to cast an object to a specific type, and returns null if it fails.
Example:
StringBuilder b = someObject as StringBuil...
Casting a variable using a Type variable
In C# can I cast a variable of type object to a variable of type T where T is defined in a Type variable?
12 Answers
...
T-SQL Cast versus Convert
What is the general guidance on when you should use CAST versus CONVERT ? Is there any performance issues related to choosing one versus the other? Is one closer to ANSI-SQL?
...
Fastest way to convert string to integer in PHP
...hing to do with the fact that intval() invokes a function call, whilst the cast is handled directly in the interpreter's expression calculator. This may also be the reason a co-ercion is even faster.
– staticsan
Oct 27 '08 at 6:09
...
Casting vs using the 'as' keyword in the CLR
When programming interfaces, I've found I'm doing a lot of casting or object type conversion.
18 Answers
...