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What is a non-capturing group in regular expressions?
How are non-capturing groups, i.e. (?:) , used in regular expressions and what are they good for?
15 Answers
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Is there a difference between foreach and map?
...n a particular language, but is there a difference between a map operation and a foreach operation? Or are they simply different names for the same thing?
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How can I repeat a character in Bash?
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You can use:
printf '=%.0s' {1..100}
How this works:
Bash expands {1..100} so the command becomes:
printf '=%.0s' 1 2 3 4 ... 100
I've set printf's format to =%.0s which means that it will always print a single = no matter what argument it is given. Therefore it prints 100 =s.
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Sorting multiple keys with Unix sort
...s that need to be sorted by 1-n keys. Some of these keys might be numeric and some of them might not be. This is a fixed-width columnar file so there are no delimiters.
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Why does integer division in C# return an integer and not a float?
Does anyone know why integer division in C# returns an integer and not a float?
What is the idea behind it? (Is it only a legacy of C/C++?)
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How to strip all non-alphabetic characters from string in SQL Server?
...t dbo.RemoveNonAlphaCharacters('abc1234def5678ghi90jkl')
Once you understand the code, you should see that it is relatively simple to change it to remove other characters, too. You could even make this dynamic enough to pass in your search pattern.
Hope it helps.
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Covariance, Invariance and Contravariance explained in plain English?
Today, I read some articles about Covariance, Contravariance (and Invariance) in Java. I read the English and German Wikipedia article, and some other blog posts and articles from IBM.
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Is there a valid reason for enforcing a maximum width of 80 characters in a code file, this day and
... column rule:
To avoid wrapping when copying code into email, web pages, and books.
To view multiple source windows side-by-side or using a side-by-side diff viewer.
To improve readability. Narrow code can be read quickly without having to scan your eyes from side to side.
I think the last point...
iOS 6 apps - how to deal with iPhone 5 screen size? [duplicate]
..., then definitely consider using Auto Layout. It removes all fixed layout handling and instead uses constraints to lay things out. Nothing will be hard-coded, and your life will become a lot simpler.
However, if you have to support older iOS's, then it really depends on your application. A majority...
Drop rows with all zeros in pandas data frame
I can use pandas dropna() functionality to remove rows with some or all columns set as NA 's. Is there an equivalent function for dropping rows with all columns having value 0?
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