Loops and Apply
For Loops
Accumulating a Total
A for loop repeats a block once for each value. Each iteration can update state.
Program
Play the script to watch value move through the loop and update total.
for_loop.R
values <- c(2, 4, 6)
total <- 0
for (value in values) {
total <- total + value
}
cat(total, "\n", sep = "")
for
`for (value in values)` repeats once per element.
accumulator
`total` keeps state across iterations.
iteration
Each pass through the loop sees a new `value`.