大约有 44,000 项符合查询结果（耗时：0.0567秒） [XML]
How to check if an appSettings key exists?
...ager.AppSettings
if (ConfigurationManager.AppSettings[name] != null)
{
// Now do your magic..
}
or
string s = ConfigurationManager.AppSettings["myKey"];
if (!String.IsNullOrEmpty(s))
{
// Key exists
}
else
{
// Key doesn't exist
}
...
Empty arrays seem to equal true and false at the same time
...comparison x ==
ToNumber(y).
The result of ToNumber(false) is 0, so we now have:
[] == 0
Again, rule #1 tells us to jump to step #14, but the next step that actually applies is #21:
21. If Type(x) is Object and Type(y) is either String or Number, return the
result of the comparison
To...
Multiple constructors in python? [duplicate]
...d
def fromfilename(cls, name):
return cls(open(name, 'rb'))
# Now you can do:
c = C(fd)
# or:
c = C.fromfilename('a filename')
Notice all those classmethods still go through the same __init__, but using classmethods can be much more convenient than having to remember what combinations...
Map function in MATLAB?
...0 8 6 4 2 ]; % the mapping array
c = zeros( 1, 10 ); % your target array
Now, typing
c( b ) = a
returns
c = 0 50 0 40 0 30 0 20 0 10
c( b ) is a reference to a vector of size 5 with the elements of c at the indices given by b. Now if you assing values to this r...
Moment JS - check if a date is today or in the future
...re:
momentObj.isAfter()
Just leave the args blank -- that'll default to now.
There's also isSameOrAfter and isSameOrBefore.
N.B. this factors in time. If you only care about the day, see Dipendu's answer.
share
...
Do git tags get pushed as well?
..., I will only every advise someone to use git push origin <tag_name> now." - copied from stackoverflow.com/a/5195913/4130619
– reducing activity
Aug 10 '15 at 16:46
...
What is the Python equivalent of Matlab's tic and toc functions?
...TicToc, marks the beginning of a time interval
toc(False)
That's it! Now we are ready to fully use tic() and toc() just as in Matlab. For example
tic()
time.sleep(5)
toc() # returns "Elapsed time: 5.00 seconds."
Actually, this is more versatile than the built-in Matlab functions. Here, ...
How do I package a python application to make it pip-installable?
...
'django-profiles',
'django-uni-forms',
],
Obviously now we have two places where dependencies are defined, but that doesn't necessarily mean that these information are duplicated: setup.py vs requirements.txt
With this setup your package should be installable via pip.
As ...
What's the $unwind operator in MongoDB?
...s.funded_year"
} }
])
If we look at the funding_rounds array, we know that for each funding_rounds, there is a raised_amount and a funded_year field. So, unwind will for each one of the documents that are elements of the funding_rounds array produce an output document. Now, in this example,...
Why prefer two's complement over sign-and-magnitude for signed numbers?
... to 4 bits for size). In the two's complement way, they are 0010 and 1111. Now, let's say I want to add them.
Two's complement addition is very simple. You add numbers normally and any carry bit at the end is discarded. So they're added as follows:
0010
+ 1111
=10001
= 0001 (discard the carry)
...