大约有 31,600 项符合查询结果（耗时：0.0449秒） [XML]
Which is faster : if (bool) or if(int)?
...s a bool as an 8-bit value, and your system ABI requires it to "promote" small (< 32-bit) integer arguments to 32-bit when pushing them onto the call stack. So to compare a bool, the compiler generates code to isolate the least significant byte of the 32-bit argument that g receives, and compares...
String.equals versus == [duplicate]
...he references to the objects are equal. Note that string constants are usually "interned" such that two constants with the same value can actually be compared with ==, but it's better not to rely on that.
if (usuario.equals(datos[0])) {
...
}
NB: the compare is done on 'usuario' because that...
Update data in ListFragment as part of ViewPager
... can get by, using its instantiateItem(ViewGroup container, int position) call. It returns reference to fragment at position position. If FragmentStatePagerAdapter already holds reference to fragment in question, instantiateItem just returns reference to that fragment, and doesn't call getItem() to ...
Hide options in a select list using jQuery
...
You cannot do this x-browser. If I recall ie has issues. The easiest thing to do is keep a cloned copy of the select before you remove items, this allows you to easily remove and then append the missing items back.
...
What is the pythonic way to detect the last element in a 'for' loop?
...r the last element in a for loop. There is a piece of code that should be called only between elements, being suppressed in the last one.
...
Difference between sh and bash
When writing shell programs, we often use /bin/sh and /bin/bash . I usually use bash , but I don't know what's the difference between them.
...
How to assign from a function which returns more than one value?
...eturningTwoValues()
If you only need the first or second component these all work too:
list[a] <- functionReturningTwoValues()
list[a, ] <- functionReturningTwoValues()
list[, b] <- functionReturningTwoValues()
(Of course, if you only needed one value then functionReturningTwoValues()[...
Optimizing away a “while(1);” in C++0x
...
Does someone have a good explanation of why this was necessary to allow?
Yes, Hans Boehm provides a rationale for this in N1528: Why undefined behavior for infinite loops?, although this is WG14 document the rationale applies to C++ as well and the document refers to both WG14 and WG21:
...
Immutability of Strings in Java
...t, and changing a reference. s2 still points to the same object as we initially set s1 to point to. Setting s1 to "Help!" only changes the reference, while the String object it originally referred to remains unchanged.
If strings were mutable, we could do something like this:
String s1 = "Hello";
St...
Windows 7 SDK installation failure
I seem to be completely unable to install the Windows 7 SDK onto my machine, and the only solution I've found on the web is to make a swathe of registry changes. I've done this - still no success.
...