Loops

Question 1

What is the recipe for a while loop in R?

Answer 1

while (cond) {
expression
}

Question 2

What statement exits a while or for loop?

Answer 2

break

Question 3

What statement skips the current iteration of a while or for loop?

Answer 3

next

Question 4

What is the recipe to loop over a vector or list in R using a for loop?

Answer 4

for (item in my_vector_or_list) {
expression
}

OR

for (i in 1:length(my_vector_or_list)) {
expression
}

Question 5

What is the recipe to loop over a matrix in R using two for loops?

Answer 5

for (i in 1:nrow(my_matrix)) {
for (j in 1:ncol(my_matrix)) {
expression
}
}