Is there a way to create a list of values from a function and then make those values into a histogram in R? I keep getting NA

I am new to the language R. I have a function and am trying to make a list that uses that function to create 1000 entries to the list, to then make a histogram.

This is my code that I have tried:

for (i in 1:1000)
   zscores[i] <- Reduce("+", runif(12)) - 6
hist(zscores)

I am getting an number for i[1] and i[1000], but for all the other entries I get NA when I should be getting a number. What am I doing wrong?

>Solution :

I didn’t get any NAs running your code this way

zscores <- c()
for (i in 1:1000) {
  zscores[i] <- Reduce("+", runif(12)) - 6
}
hist(zscores)

Or running the way Gregor Thomas mention

zscores <- c()
for (i in 1:1000) {
  zscores[i] <- sum(runif(12)) - 6
}
hist(zscores)