R Control Structures and Functions Cheat Sheet (DRAFT) by mainul12

if (condition) {
       ## do something
} else {
       ## do something else
}

if (x > 3) {
          y <- 10
} else {
          y <- 0
}

for (i in 1:10) {
          print(i)
}

## The following loops have the same behavior

x <- c("a","b","c","d")

for (i in 1:4) {
          print(x[i])
}

for (i in seq_along(x)) {
          print(x[i])
}

for (letter in x) {
          print(letter)
}

## If a for loop has a single expression

for (i in 1:4) print(x[i])

count <- 0

while (count < 10){
          print(count)
          count <- count + 1
}

x0 <- 1
tol <- 1e-8

repeat {
           x1 <- somefunction()
           if (condition) {
                        break
           } else {
                        (another condition)
           }
}

for (i in 1:100) {
          if (i <= 20) {
                    # Skip the first 20 iterations
                    next
          }
          ## Do something here
}

add2 <- function(x + y) {
             x + y
}

## A function always returns the last expression

above <- function(x, n) {
              use <- x > n
              x[use]
}