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What must I know to use GNU Screen properly? [closed]
...n and they're having a hard time getting used to it. That makes me think about the essential things he needs to know about the excellent Screen utility, the same things that you'd think worthwhile to teach someone, a beginner, from the ground up. What are some analogies and handy tips for remembe...
What does the 'b' character do in front of a string literal?
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To quote the Python 2.x documentation:
A prefix of 'b' or 'B' is ignored in
Python 2; it indicates that the
literal should become a bytes literal
in Python 3 (e.g. when code is
automatically converted with 2to3). A
'u' or 'b' prefix may be followed by
an 'r' prefix...
Scala 2.8 breakOut
In Scala 2.8 , there is an object in scala.collection.package.scala :
4 Answers
4
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Default argument values in JavaScript functions [duplicate]
...ut parameters.
So you can add default values like this:
function func(a, b){
if (typeof(a)==='undefined') a = 10;
if (typeof(b)==='undefined') b = 20;
//your code
}
and then you can call it like func(); to use default parameters.
Here's a test:
function func(a, b){
if (typeof(a)==...
Java optional parameters
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varargs could do that (in a way). Other than that, all variables in the declaration of the method must be supplied. If you want a variable to be optional, you can overload the method using a signature which doesn't require the parameter.
private boolean defaultOptionalFlagValue = tru...
Append value to empty vector in R?
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Appending to an object in a for loop causes the entire object to be copied on every iteration, which causes a lot of people to say "R is slow", or "R loops should be avoided".
As BrodieG mentioned in the comments: it is much better to pre-al...
Replace a value in a data frame based on a conditional (`if`) statement
In the R data frame coded for below, I would like to replace all of the times that B
appears with b .
8 Answers
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Understanding how recursive functions work
...lains I have a very fundamental programming question which I have just not been able to grok yet. Filtering out all of the (extremely clever) "In order to understand recursion, you must first understand recursion." replies from various online threads I still am not quite getting it.
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How to sort an array of objects by multiple fields?
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A multi dimensional sorting method, based on this answer:
Update: Here is an "optimized" version. It does a lot more preprocessing and creates a comparison function for each sorting option beforehand. It might need more more memory (as it stores a function for...
Does the Java &= operator apply & or &&?
... T is the type of E1, except that E1 is evaluated only once.
So a &= b; is equivalent to a = a & b;.
(In some usages, the type-casting makes a difference to the result, but in this one b has to be boolean and the type-cast does nothing.)
And, for the record, a &&= b; is not valid...