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How to perform runtime type checking in Dart?
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is and is! can be found in the Operators section of the Dart language tour.
– Curly
Jun 25 '19 at 16:02
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For each row in an R dataframe
I have a dataframe, and for each row in that dataframe I have to do some complicated lookups and append some data to a file.
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Checking out Git tag leads to “detached HEAD state”
I'm developing a deployment script for my git project and I just started using tags. I've added a new tag called v2.0 :
2 ...
Replace selector images programmatically
... resource set to a selector. How do I programmatically access the selector and change the images of the highlighted and non-highlighted state?
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Sorting arraylist in alphabetical order (case insensitive)
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can u tell me what is string s1 and s2?and how can see the result if the compare function returning integer value.
– andro-girl
Apr 28 '11 at 8:01
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How do I check if a SQL Server text column is empty?
I am using SQL Server 2005. I have a table with a text column and I have many rows in the table where the value of this column is not null, but it is empty. Trying to compare against '' yields this response:
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Dynamically Changing log4j log level
...ife cyle of the Logger. On reinitialization the configuration will be read and used as setting the level at runtime does not persist the level change.
UPDATE: If you are using Log4j 2 you should remove the calls to setLevel per the documentation as this can be achieved via implementation classes.
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How to scroll to an element inside a div?
I have a scrolled div and I want to have an event when I click on it, it will force this div to scroll to view an element inside.
I wrote its JavasSript like this:
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Index on multiple columns in Ruby on Rails
...:user_id, :article_id], you can perform a fast query on user_id or user_id AND article_id, but NOT on article_id.
Your migration add_index line should look something like this:
add_index :user_views, [:user_id, :article_id]
Question regarding 'unique' option
An easy way to do this in Rails ...
Convert audio files to mp3 using ffmpeg
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You could use this command:
ffmpeg -i input.wav -vn -ar 44100 -ac 2 -b:a 192k output.mp3
Explanation of the used arguments in this example:
-i - input file
-vn - Disable video, to make sure no video (including album cover image) is included if...