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Why is there a difference in checking null against a value in VB.NET and C#?
...I don't know yet". Then the comparison of 5 to "I don't know yet". is naturally "I don't know yet"; ie NULL. This has the additional advantage of mirroring the behaviour of NULL in (most if not all) SQL databases. This is also a more standard (than C#'s) interpretation of three-valued logic, as expl...
Create a “with” block on several context managers? [duplicate]
...rite:
with A() as X, B() as Y, C() as Z:
do_something()
This is normally the best method to use, but if you have an unknown-length list of context managers you'll need one of the below methods.
In Python 3.3, you can enter an unknown-length list of context managers by using contextlib.Exit...
How do I recursively delete a directory and its entire contents (files + sub dirs) in PHP?
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This calls is_dir twice for each recursed directory. If the argument is a symlink, it also follows it instead of deleting the symlink, which might or might not be what you want. In any case, it's not what rm -rf does.
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Why .NET String is immutable? [duplicate]
As we all know, String is immutable. What are the reasons for String being immutable and the introduction of StringBuilder class as mutable?
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Output array to CSV in Ruby
...enerate_line(row) }.join("")
#=> "a1,a2,a3\nb1,b2,b3\nc1,c2,c3\n"
Do all of the above and save to a csv, in one line.
File.open("ss.csv", "w") {|f| f.write(rows.inject([]) { |csv, row| csv << CSV.generate_line(row) }.join(""))}
NOTE:
To convert an active record database to csv would...
os.walk without digging into directories below
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Does this function actually "walk" through the whole structure and then delete the entries below a certain point? Or is something more clever going on? I'm not even sure how to check this with code. --python beginner
– mathtic...
Vim clear last search highlighting
After doing a search in Vim, I get all the occurrences highlighted. How can I disable that? I now do another search for something gibberish that can't be found.
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Download data url file
... just drag their zip directly into the browser and it'll let them download all the files within. They can also create new zip files by dragging individual files in.
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Difference between null and empty (“”) Java String
... String("");
System.out.println(a==b);
That would output false because I allocated two different objects, and a and b point to different objects.
However, a.equals(b) in this case would return true, because equals for Strings will return true if and only if the argument String is not null and rep...
Recursively counting files in a Linux directory
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Actually, on some platforms, you do need to spell out find .
– tripleee
Jun 8 '19 at 8:33
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