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Find objects between two dates MongoDB
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I just used this to convert my strings to date objects stackoverflow.com/questions/2900674/…
– Tom
May 31 '10 at 21:07
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Is it better in C++ to pass by value or pass by constant reference?
...d be able to figure out when passing by value is expensive, and implicitly convert the call to use a const ref if possible.
In theory. In practice, compilers can’t always change this without breaking the function’s binary interface. In some special cases (when the function is inlined) the copy ...
Checking to see if a DateTime variable has had a value assigned
... null to start with and then assign a normal DateTime value (which will be converted appropriately). Then you can just compare with null (or use the HasValue property) to see whether a "real" value has been set.
share
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When to use the brace-enclosed initializer?
...no constructor taking std::initializer_list interfering. Similarly std::is_convertible is of no help.
I've investigated if it is in fact possible to hand-roll a trait that can fix that but I'm not overly optimistic about that. In any case I don't think we would be missing much, I think that the fac...
Writing to an Excel spreadsheet
...ures and will let you read in excel files as well.
You will first have to convert your data into a DataFrame and then save it into an excel file like so:
In [1]: from pandas import DataFrame
In [2]: l1 = [1,2,3,4]
In [3]: l2 = [1,2,3,4]
In [3]: df = DataFrame({'Stimulus Time': l1, 'Reaction Time':...
Command-line Unix ASCII-based charting / plotting tool
... gnuplot -persist"
printAndRun(com)
# ---- convert to PDF
An example of use:
[$]> git shortlog -s -n | awk '{print $1}' | eplot 2> /dev/null
3500 ++-------+-------+--------+--------+-------+--------+-------+-------++
+ + + "/tmp...
Making the iPhone vibrate
...rror for trying to cast from Int to UInt32, but the error reads as "Cannot convert to SystemSoundID", which is confusing. Why didn't apple just make it a Swift enum is beyond me.
@aponomarenko's goes into the details, my answer is just for the Swifters out there.
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How do I format a number in Java?
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When you want to convert the rounded value as string, this is one of the way. Other is using DecimalFormat. And DecimalFormat is slightly faster than String.format. Simple System.currentTimeMillis diff reveals that.
– ma...
Why is address zero used for the null pointer?
... differently at runtime. The C++ standard has a note that makes clear that converting "an integral constant expression with value zero always yields a null pointer, but converting other expressions that happen to have value zero need not yield a null pointer".
a negative value might be just as usabl...
Immutable array in Java
...his can actually come in handy if you are using the List.toArray method to convert a List to an array. Since even an empty array takes up some memory, you can save that memory allocation by creating a constant empty array, and always passing it to the toArray method. That method will allocate a new ...