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How is a CRC32 checksum calculated?
...ybe I'm just not seeing it, but CRC32 seems either needlessly complicated, or insufficiently explained anywhere I could find on the web.
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How to match “any character” in regular expression?
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Yes, you can. That should work.
. = any char
\. = the actual dot character
.? = .{0,1} = match any char zero or one times
.* = .{0,} = match any char zero or more times
.+ = .{1,} = match any char one or more times
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Reference — What does this symbol mean in PHP?
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Incrementing / Decrementing Operators
++ increment operator
-- decrement operator
Example Name Effect
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++$a Pre-increment Increments $a by one, then returns $a.
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How to make Regular expression into non-greedy?
...xt from that special characters block. I used a regular expression object for in-string finding. But how can I tell jQuery to find multiple results when have two special character or more?
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What exactly is an Assembly in C# or .NET?
Could you please explain what is an Assembly in C# or .NET?
9 Answers
9
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How do I concatenate or merge arrays in Swift?
...g a new array
let c = a + b
print(c) // [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]
or append one array to the other with += (or append):
a += b
// Or:
a.append(contentsOf: b) // Swift 3
a.appendContentsOf(b) // Swift 2
a.extend(b) // Swift 1.2
print(a) // [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]
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Regex exactly n OR m times
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There is no single quantifier that means "exactly m or n times". The way you are doing it is fine.
An alternative is:
X{m}(X{k})?
where m < n and k is the value of n-m.
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How do I check in JavaScript if a value exists at a certain array index?
Will this work for testing whether a value at position index exists or not, or is there a better way:
18 Answers
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Shell equality operators (=, ==, -eq)
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It's the other way around: = and == are for string comparisons, -eq is for numeric ones. -eq is in the same family as -lt, -le, -gt, -ge, and -ne, if that helps you remember which is which.
== is a bash-ism, by the way. It's better to use the POSIX =. In bash the t...
Difference in System. exit(0) , System.exit(-1), System.exit(1 ) in Java
...parameter of exit should qualify if the execution of the program went good or bad. It's a sort of heredity from older programming languages where it's useful to know if something went wrong and what went wrong.
Exit code is
0 when execution went fine;
1, -1, whatever != 0 when some error occurred...