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Performance difference for control structures 'for' and 'foreach' in C#
...corlib]System.IDisposable::Dispose()
IL_002f: endfinally
} // end handler
IL_0030: ret
} // end of method Test::IterateOverList
The compiler treats arrays differently, converting a foreach loop basically to a for loop, but not List<T>. Here's the equivalent code for an array:
sta...
What does %~dp0 mean, and how does it work?
I find %~dp0 very useful, and I use it a lot to make my batch files more portable.
7 Answers
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Crontab Day of the Week syntax
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0 and 7 both stand for Sunday, you can use the one you want, so writing 0-6 or 1-7 has the same result.
Also, as suggested by @Henrik, it is possible to replace numbers by shortened name of days, such as MON, THU, etc:
0 - Su...
Why aren't ◎ܫ◎ and ☺ valid JavaScript variable names?
...sers I tested), you can use some Unicode variable names. This made my day, and I was absolutely delighted that I could write fun Unicode-laden code like this:
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Analyze audio using Fast Fourier Transform
...you need to calculate the square root of the sum of the square of its real and imaginary components. That is, if your coefficient is a + b*j, then its magnitude is sqrt(a^2 + b^2).
Once you have calculated the magnitude of each FFT coefficient, you need to figure out which audio frequency each FFT ...
“x not in y” or “not x in y”
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They always give the same result.
In fact, not 'ham' in 'spam and eggs' appears to be special cased to perform a single "not in" operation, rather than an "in" operation and then negating the result:
>>> import dis
>>> def notin():
'ham' not in 'spam and eggs'
&g...
How do I scroll the UIScrollView when the keyboard appears?
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Following code is copied from the Keyboard Programming Guide, where the handling of this issue is explained. You should have a look into it.
// Call this method somewhere in your view controller setup code.
- (void)registerForKeyboardNotifications
{
[[NSNotificationCenter defaultCenter] addOb...
How to check if a value exists in a dictionary (python)
...t()
[0.32004380226135254, 0.31716084480285645, 0.3171098232269287]
EDIT: And in case you wonder why... the reason is that each of the above returns a different type of object, which may or may not be well suited for lookup operations:
>>> type(d.viewvalues())
<type 'dict_values'>
&...
How to add a new audio (not mixing) into a video using ffmpeg?
I used a command like:
7 Answers
7
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What is the difference between trie and radix trie data structures?
Are the trie and radix trie data structures the same thing?
3 Answers
3
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