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Understanding prototypal inheritance in JavaScript
...ease explain the difference between the following blocks of code? I tested and both blocks work. What's the best practice and why?
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Drop unused factor levels in a subsetted data frame
...t, so the mydf <- droplevels(mydf) solution suggested by Roman Luštrik and Tommy O'Dell below is preferable.
– Johan
May 9 '14 at 10:41
1
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what is the difference between ?:, ?! and ?= in regex?
I searched for the meaning of these expressions but couldn't understand the exact difference between them.
This is what they say:
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Handling Dialogs in WPF with MVVM
In the MVVM pattern for WPF, handling dialogs is one of the more complex operations. As your view model does not know anything about the view, dialog communication can be interesting. I can expose an ICommand that when the view invokes it, a dialog can appear.
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Test if object implements interface
...eding to cast afterward with the first one thus giving you two casts ("is" and then an explicit cast). With the second approach you only cast once.
– Andrew Hare
Jan 4 '09 at 6:02
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Screenshot Apps for iPhone simulator [closed]
... from which version of the iOS Simulator is this possible, but it's better and faster!
You can also try cmd+ctrl+C while in the iOS simulator. Then open Preview or an image editing program and try cmd+N (the image is in the clipboard).
Edit: According to apple's new guidelines we need to provide hig...
Simple state machine example in C#?
...is simple state diagram:
We have:
4 states (Inactive, Active, Paused, and Exited)
5 types of state transitions (Begin Command, End Command, Pause Command, Resume Command, Exit Command).
You can convert this to C# in a handful of ways, such as performing a switch statement on the current state...
Handling Touch Event in UILabel and hooking it up to an IBAction
...rner try the tag property. make sure to use labelTap: instead of labelTap. and use - (void) labelTap:(id)sender;.
– thedjaney
Jul 28 '14 at 9:43
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How to add ASP.NET 4.0 as Application Pool on IIS 7, Windows 7
...re you have IIS installed then perform the following steps:
Open your command prompt (Windows + R) and type cmd and press ENTER
You may need to start this as an administrator if you have UAC enabled.
To do so, locate the exe (usually you can start typing with Start Menu open), right click and selec...
Collapse sequences of white space into a single character and trim string
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OS X 10.7+ and iOS 3.2+
Use the native regexp solution provided by hfossli.
Otherwise
Either use your favorite regexp library or use the following Cocoa-native solution:
NSString *theString = @" Hello this is a long ...