Select random element in a list of R?

Question

a<-c(1,2,0,7,5)

Some languages have a picker -function -- choose one random number from a -- how in R?

Answer 1

Be careful when using sample!

sample(a, 1) works great for the vector in your example, but when the vector has length 1 it may lead to undesired behavior, it will use the vector 1:a for the sampling.

So if you are trying to pick a random item from a varying length vector, check for the case of length 1!

sampleWithoutSurprises <- function(x) {
  if (length(x) <= 1) {
    return(x)
  } else {
    return(sample(x,1))
  }
}