大约有 41,000 项符合查询结果（耗时：0.0405秒） [XML]
Double negation (!!) in javascript - what is the purpose? [duplicate]
...
It casts to boolean. The first ! negates it once, converting values like so:
undefined to true
null to true
+0 to true
-0 to true
'' to true
NaN to true
false to true
All other expressions to false
Then the other ! negates i...
capturing self strongly in this block is likely to lead to a retain cycle
...ple of members of self in this block, most likely just to update a slider. Casting self is overkill. Instead, it's better to be explicit and cast only the objects that you truly need inside the block. For example, if it's an instance of UISlider*, say, _timeSlider, just do the following before the b...
How do you implement a class in C? [closed]
...s the proper class, i.e. RectangleClass *. This means you often have to do casts, but they provide handy macros do help with that, so you can always cast BASECLASS *p to SUBCLASS * using just SUBCLASS(p).
– unwind
Sep 10 '09 at 8:03
...
How to convert IEnumerable to ObservableCollection?
...ble original)
{
return new ObservableCollection<object>(original.Cast<object>());
}
If you're working with generic IEnumerable<T> you can do it this way:
public ObservableCollection<T> Convert<T>(IEnumerable<T> original)
{
return new ObservableCollection...
How different is Objective-C from C++? [closed]
...Objective-C is a more perfect superset of C. In C and Objective-C implicit casting from void* to a struct pointer is allowed.
Foo* bar = malloc(sizeof(Foo));
C++ will not compile unless the void pointer is explicitly cast:
Foo* bar = (Foo*)malloc(sizeof(Foo));
The relevance of this to every da...
Which one will execute faster, if (flag==0) or if (0==flag)?
...caveat: Nawaz did point out the user-defined trap. And I regret my hastily cast upvote on "stupidest question" because it seems that many did not get it right and it gives room for a nice discussion on compiler optimization :)
The answer is:
What is flag's type?
In the case where flag actuall...
Pass data to layout that are common to all pages
...u need for the layout, why bother adding it to the ViewBag only to have to cast it back again? Use the model in the layout view, you can still populate the model in OnActionExecuting. Using ViewBag also means you loose type safety in your controller, never a good thing.
– Colin...
How do you specify that a class property is an integer?
...r markers
foo.someId = 2;
foo.someInt = 1;
// when assigning, you have to cast to the specific type
// NOTE: This is not completely type safe as you can trick the compiler
// with something like foo.someId = 1.45 as ID and it won't complain.
foo.someId = 2 as ID;
foo.someInt = 1 as Int;
// you ca...
Best way to convert IList or IEnumerable to Array
...omething like this:
IEnumerable query = ...;
MyEntityType[] array = query.Cast<MyEntityType>().ToArray();
If you don't know the type within that method but the method's callers do know it, make the method generic and try this:
public static void T[] PerformQuery<T>()
{
IEnumerabl...
What is an idiomatic way of representing enums in Go?
... literal value 42, which the function would accept as base since it can be casted to an int. To prevent this, make base a struct: type base struct{value:int}. Problem: you cannot declare bases as constants anymore, only module variables. But 42 will never be cast to a base of that type.
...