purrr map equivalent of nested for loop

Question

What is the purrr::map equivalent of:

for (i in 1:4) {
  for (j in 1:6) {
    print(paste(i, j, sep = \"-\"))
  }
}

OR

lap         


        

Answer 1

Just Running through this now.

walk(1:4,~ walk(1:6, ~ print(paste(.x, .y, sep = "-")),.y=.x)) 
[1] "1-1"
[1] "2-1"
[1] "3-1"
[1] "4-1"
[1] "5-1"
[1] "6-1"
[1] "1-2"

and

purrr::pwalk(expand.grid(1:4,1:6),~print(paste(.x, .y, sep = "-")))
[1] "1-1"
[1] "2-1"
[1] "3-1"
[1] "4-1"
[1] "1-2"

but to match your nested for loops exactly it fiddled and this works.

for (i in 1:4) {
  for (j in 1:6) {
    print(paste(i, j, sep = "-"))
  }
}
[1] "1-1"
[1] "1-2"
[1] "1-3"
[1] "1-4"
[1] "1-5"
[1] "1-6"
[1] "2-1"

purrr::pwalk(expand.grid(1:6,1:4),~print(paste(.y, .x, sep = "-")))
[1] "1-1"
[1] "1-2"
[1] "1-3"
[1] "1-4"
[1] "1-5"
[1] "1-6"
[1] "2-1"

#or even a map of this
walk(1:4,~ walk(1:6, ~ print(paste(.y, .x, sep = "-")),.y=.x))

I have yet to figure out why the .y=.x is at the end though.