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Difference between events and delegates and its respective applications [closed]
...en certain conditions are met. For example, my Stock class has a property called Limit, and it raises an event when the stock prices reaches the Limit. This notification is done via an event. Whether anyone actually cares about this event and subscribes to it is beyond the concern of the owner class...
How to delete from a text file, all lines that contain a specific string?
How would I use sed to delete all lines in a text file that contain a specific string?
17 Answers
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Normal arguments vs. keyword arguments
How are "keyword arguments" different from regular arguments? Can't all arguments be passed as name=value instead of using positional syntax?
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How to create a directory and give permission in single command
... in the path you type. For example, mkdir -p -m 707 one/two/three. Even if all three directories are newly created, only the last one will have the requested permissions, and the others, default. install -d -m is broken the same way.
– Display Name
May 6 '15 at...
Bootstrap 3 and 4 .container-fluid with grid adding unwanted padding
...anks a bunch. I'd like to remove it when I'm using a column, though. I really don't want to mess with the core bootstrap css. I suspect there must be a sanctioned way to do this. Any thoughts?
– Tim
Aug 22 '14 at 13:22
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How does one reorder columns in a data frame?
... has four columns like so df[,c(1,2,3,4)].
Note the first comma means keep all the rows, and the 1,2,3,4 refers to the columns.
To change the order as in the above question do df2[,c(1,3,2,4)]
If you want to output this file as a csv, do write.csv(df2, file="somedf.csv")
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Add file extension to files with bash
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second one adds an extension on all files, not just extensionless ones
– Jeff
Mar 24 '15 at 15:55
5
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Initializing multiple variables to the same value in Java
...n, thirdPerson;
firstPerson = secondPerson = thirdPerson = new Person();
All the variables would be pointing to the same instance. Probably what you would need in that case is:
Person firstPerson = new Person();
Person secondPerson = new Person();
Person thirdPerson = new Person();
Or better ye...
Class with single method — best approach?
...lity either before or after the old method, we can create a new class and call the old one inside of it - but that's just gross.
Interface woes
Static methods cannot be defined through interfaces for logic reasons. And since we can't override static methods, static classes are useless when we need ...
Virtual functions and performance - C++
...e a very slight effect on performance, but it's unlikely to affect the overall performance of your application. Better places to look for performance improvements are in algorithms and I/O.
An excellent article that talks about virtual functions (and more) is Member Function Pointers and the Fastes...