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What special characters must be escaped in regular expressions?
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Which characters you must and which you mustn't escape indeed depends on the regex flavor you're working with.
For PCRE, and most other so-called Perl-compatible flavors, escape these outside character classes:
.^$*+?()[{\|
and these inside charac...
Is there a regular expression to detect a valid regular expression?
...group start
(?:
(?:[^?+*{}()[\]\\|]+ # literals and ^, $
| \\. # escaped characters
| \[ (?: \^?\\. | \^[^\\] | [^\\^] ) # character classes
(?: [^\]\\]+ | \\. )* \]
| \( (?:\?[:=!]|\?<[=!]|\?>)? (?1)?? ...
Restart node upon changing a file
For someone who is coming from PHP background the process of killing node and starting it again after every code change, seems very tedious. Is there any flag when starting a script with node to automatically restart node when code change is saved?
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What is the difference between .*? and .* regular expressions?
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It is the difference between greedy and non-greedy quantifiers.
Consider the input 101000000000100.
Using 1.*1, * is greedy - it will match all the way to the end, and then backtrack until it can match 1, leaving you with 1010000000001.
.*? is non-greedy. * w...
When should I use Debug.Assert()?
...graduated with a CS degree. I've known about assertions for a while in C++ and C, but had no idea they existed in C# and .NET at all until recently.
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How can I check if a string represents an int, without using try/except?
... is an int, so does your program. If Python changes, so does your program, and without changing a single line of code. There's some value in that. It might be the right thing to do depending on the circumstances.
– Shavais
Oct 8 '14 at 16:07
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Why are private fields private to the type, not the instance?
In C# (and many other languages) it's perfectly legitimate to access private fields of other instances of the same type. For example:
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What is an idempotent operation?
...g that x in the mathematical definition represents the state of an object, and f is an operation that may mutate that object. For example, consider the Python set and its discard method. The discard method removes an element from a set, and does nothing if the element does not exist. So:
my_set.dis...
Recursively look for files with a specific extension
I'm trying to find all files with a specific extension in a directory and its subdirectories with my bash (Latest Ubuntu LTS Release).
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CSS: Animation vs. Transition
So, I understand how to perform both CSS3 transitions and animations . What is not clear, and I've googled, is when to use which.
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