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Why does ~True result in -2?
...00000001
and ~1 is:
11111110
Which is -2 in Two's complement1
1 Flip all the bits, add 1 to the resulting number and interpret the result as a binary representation of the magnitude and add a negative sign (since the number begins with 1):
11111110 → 00000001 → 00000010
↑ ...
Setting the filter to an OpenFileDialog to allow the typical image formats?
I have this code, how can I allow it to accept all typical image formats? PNG, JPEG, JPG, GIF?
11 Answers
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Difference between Observer, Pub/Sub, and Data Binding
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Here's my take on the three:
Data Binding
Essentially, at the core this just means "the value of property X on object Y is semantically bound to the value of property A on object B. No assumptions are made as to how Y knows or is fed changes on object B.
Observer, or Obser...
Truncate all tables in a MySQL database in one command?
Is there a query (command) to truncate all the tables in a database in one operation? I want to know if I can do this with one single query.
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What is the behavior difference between return-path, reply-to and from?
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Now, let's describe the different "FROM"s.
The return path (sometimes called the reverse path, envelope sender, or envelope from — all of these terms can be used interchangeably) is the value used in the SMTP session in the MAIL FROM command. As you can see, this does not need to be the same v...
Which iomanip manipulators are 'sticky'?
... the comments below:
By Martin:
@Chareles: Then by this requirement all manipulators are sticky. Except setw which seems to be reset after use.
By Charles:
Exactly! and the only reason that setw appears to behave differently is because there are requirements on formatted output operat...
Using -performSelector: vs. just calling the method
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Basically performSelector allows you to dynamically determine which selector to call a selector on the given object. In other words the selector need not be determined before runtime.
Thus even though these are equivalent:
[a...
Get OS-level system information
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You can get some limited memory information from the Runtime class. It really isn't exactly what you are looking for, but I thought I would provide it for the sake of completeness. Here is a small example. Edit: You can also get disk usage information from the java.io.File class. The disk space us...
How do I view all commits for a specific day?
...:00" --until="2013-11-13 00:00" & would also work if you have gitk installed.
– HelloGoodbye
Mar 4 '16 at 12:50
6
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What is the difference between Directory.EnumerateFiles vs Directory.GetFiles?
...many files and directories, EnumerateFiles can be more efficient.
So basically, EnumerateFiles returns an IEnumerable which can be lazily evaluated somewhat, whereas GetFiles returns a string[] which has to be fully populated before it can return.
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