大约有 11,600 项符合查询结果（耗时：0.0162秒） [XML]
Why don't structs support inheritance?
I know that structs in .NET do not support inheritance, but its not exactly clear why they are limited in this way.
10 An...
What is the meaning of single and double underscore before an object name?
Can someone please explain the exact meaning of having leading underscores before an object's name in Python, and the difference between both?
...
Why does Decimal.Divide(int, int) work, but not (int / int)?
How come dividing two 32 bit int numbers as ( int / int ) returns to me 0 , but if I use Decimal.Divide() I get the correct answer? I'm by no means a c# guy.
...
Why doesn't Python have a sign function?
I can't understand why Python doesn't have a sign function. It has an abs builtin (which I consider sign 's sister), but no sign .
...
Is there a printf converter to print in binary format?
I can print with printf as a hex or octal number. Is there a format tag to print as binary, or arbitrary base?
52 Answer...
How can I use map and receive an index as well in Scala?
Is there any List/Sequence built-in that behaves like map and provides the element's index as well?
8 Answers
...
Why can't non-default arguments follow default arguments?
...
All required parameters must be placed before any default arguments. Simply because they are mandatory, whereas default arguments are not. Syntactically, it would be impossible for the interpreter to decide which values match which arguments if mixed mod...
Finish an activity from another activity
...When the user clicks modify, call the new Intent or simply finish activity B.
FIRST WAY
In your first activity, declare one Activity object like this,
public static Activity fa;
onCreate()
{
fa = this;
}
now use that object in another Activity to finish first-activity like this,
onCreate(...
Is it better to call ToList() or ToArray() in LINQ queries?
...ase where I want to eval a query right where I declare it. This is usually because I need to iterate over it multiple times and it is expensive to compute. For example:
...
Element-wise addition of 2 lists?
...>> %timeit from operator import add;map(add, list1, list2)
10 loops, best of 3: 44.6 ms per loop
>>> %timeit from itertools import izip; [a + b for a, b in izip(list1, list2)]
10 loops, best of 3: 71 ms per loop
>>> %timeit [a + b for a, b in zip(list1, list2)]
10 loops, best...