switch statement help in R -

i've got following code in r:

func.time <- function(n){ times <- c() for(i in 1:n){  r <- 1 #x room mouse in x <- 0 #time, starting @ 0 while(r != 5){  if(r == 1){     r <- sample(c(2,3),1) }  else if(r == 2){     r <- sample(c(1,3), 1) }  else if(r == 3){     r <- sample(c(1,2,4,5), 1) }  else if (r == 4){     r <- sample(c(3,5), 1) }   x <- x + 1  }   times <- c(x, times)  }  mean(times)  }  func.time(10000) 

it works fine, i've been told using switch() can speed seeing i've got many if else statements can't seem work, appreciated in advance.

edit i've tried this:

func.time <- function(n) {     times <- c()      for(i in 1:n) {         r <- 1 #x room mouse in          x <- 0 #time, starting @ 0          while(r != 5) {              switch(r, "1" = sample(c(2,3), 1),                          "2" = sample(c(1,3), 1),                          "3" = sample(c(1,2,4,5), 1),                          "4" = sample(c(3,5)))              x <- x + 1          }          times <- c(x, times)      }      mean(times)  }   func.time(10000) 

but basic attempt, i'm not sure i've understood switch() method properly.

i though dominic's assessment useful when went examine edit being held on thought incorrect basis. decided fix code. when usign numeric argument expr parameter not use item=value formalism rather put in expressions:

 func.time <- function(n){times <- c()      for(i in 1:n){; r <- 1; x <- 0          while(r != 5){              r <- switch(r,                    sample(c(2,3), 1) ,  # r=1                   sample(c(1,3), 1) ,  # r=2                   sample(c(1,2,4,5), 1), #r=3                   sample(c(3,5), 1)  ) # r=4             x <- x + 1 }          times <- c(x, times) }           mean(times) }   func.time(1000) #[1] 7.999 

for example of how use switch numeric argument expr, consider answer question: r switch statement varying outputs throwing error