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How to Correctly Use Lists in R?
...st?) contemporary programming languages in widespread use have at least a handful of ADTs [abstract data types] in common, in particular,
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How do you know when to use fold-left and when to use fold-right?
I'm aware that fold-left produces left-leaning trees and fold-right produces right-leaning trees, but when I reach for a fold, I sometimes find myself getting bogged down in headache-inducing thought trying to determine which kind of fold is appropriate. I usually end up unwinding the entire proble...
Does return stop a loop?
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Yes, return stops execution and exits the function. return always** exits its function immediately, with no further execution if it's inside a for loop.
It is easily verified for yourself:
function returnMe() {
for (var i = 0; i < 2; i++) {
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biggest integer that can be stored in a double
...more do you want?
Go on, ask me what the largest integer is, such that it and all smaller integers can be stored in IEEE 64-bit doubles without losing precision. An IEEE 64-bit double has 52 bits of mantissa, so I think it's 253:
253 + 1 cannot be stored, because the 1 at the start and the 1 at t...
Differences between “BEGIN RSA PRIVATE KEY” and “BEGIN PRIVATE KEY”
Hi I was writing a program that imports private keys from a .pem file and create a private key object to use it later..
the problem I have faced is that some pem files header begin with
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Callback functions in C++
In C++, when and how do you use a callback function?
10 Answers
10
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Sort points in clockwise order?
...e other.
Using it you can construct a less-than relation to compare points and determine the order in which they should appear in the sorted array. But you have to define where is the beginning of that order, I mean what angle will be the starting one (e.g. the positive half of x-axis).
The code fo...
How to access the last value in a vector?
... vector that is nested in a dataframe one or two levels. Is there a quick and dirty way to access the last value, without using the length() function? Something ala PERL's $# special var?
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When should I use Struct vs. OpenStruct?
In general, what are the advantages and disadvantages of using an OpenStruct as compared to a Struct? What type of general use-cases would fit each of these?
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Is there a builtin identity function in python?
...ng some more research, there is none, a feature was asked in issue 1673203 And from Raymond Hettinger said there won't be:
Better to let people write their own trivial pass-throughs
and think about the signature and time costs.
So a better way to do it is actually (a lambda avoids naming the...