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Difference between single and double quotes in Bash
...o "upg")"
upg
$ echo '$(echo "upg")'
$(echo "upg")
The Bash manual has this to say:
3.1.2.2 Single Quotes
Enclosing characters in single quotes (') preserves the literal value of each character within the quotes. A single quote may not occur between single quotes, even when preceded by a ...
Java Try Catch Finally blocks without Catch
...e. The program has a try and a finally block only. Since the catch block is excluded, how does the try block work if it encounters an exception or anything throwable? Does it just go directly to the finally block?
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getting exception “IllegalStateException: Can not perform this action after onSaveInstanceState”
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This is the most stupid bug I have encountered so far. I had a Fragment application working perfectly for API < 11, and Force Closing on API > 11.
I really couldn't figure out what they changed inside the Activity lifecy...
Cutting the videos based on start and end time using ffmpeg
...f the data starting with the previous keyframe.
With the mp4 container it is possible to cut at a non-keyframe without re-encoding using an edit list. In other words, if the closest keyframe before 3s is at 0s then it will copy the video starting at 0s and use an edit list to tell the player to st...
What is the effect of extern “C” in C++?
...t contains just the declaration of your function. Your function definition is contained in a binary format (that was compiled by your C++ compiler) that the client C linker will then link to using the C name.
Since C++ has overloading of function names and C does not, the C++ compiler cannot just us...
Convert a character digit to the corresponding integer in C
Is there a way to convert a character to an integer in C?
15 Answers
15
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How to Update Multiple Array Elements in mongodb
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At this moment it is not possible to use the positional operator to update all items in an array. See JIRA http://jira.mongodb.org/browse/SERVER-1243
As a work around you can:
Update each item individually
(events.0.handled eve...
Interfaces with static fields in java for sharing 'constants'
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It's generally considered bad practice. The problem is that the constants are part of the public "interface" (for want of a better word) of the implementing class. This means that the implementing class is publishing all of these values to external classes even when they are ...
How do I merge two dictionaries in a single expression in Python (taking union of dictionaries)?
...hon 3.9.0a4 or greater (final release date approx October 2020): PEP-584, discussed here, was implemented to further simplify this:
z = x | y # NOTE: 3.9+ ONLY
Explanation
Say you have two dictionaries and you want to merge them into a new dict without altering the original dictionaries:...
Strtotime() doesn't work with dd/mm/YYYY format
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Here is the simplified solution:
$date = '25/05/2010';
$date = str_replace('/', '-', $date);
echo date('Y-m-d', strtotime($date));
Result:
2010-05-25
The strtotime documentation reads:
Dates in the m/d/y or d-m-y formats...