Introduction to Control Flow in R

Control flow statements allow you to control the execution of your code using conditions and loops.

Using if Statements

The if statement runs code only if a condition is true.

x <- 10
if (x > 5) {
  print('x is greater than 5')
}

Using if-else Statements

The if-else statement provides an alternative when the condition is false.

x <- 3
if (x > 5) {
  print('x is greater than 5')
} else {
  print('x is not greater than 5')
}

Using ifelse() Function

The ifelse() function is a vectorized version of if-else.

x <- c(2, 7, 5)
ifelse(x > 5, 'High', 'Low')

Using for Loops

A for loop repeats a block of code for a fixed number of times.

for (i in 1:5) {
  print(i)
}

Using while Loops

A while loop runs as long as the condition is true.

x <- 1
while (x <= 5) {
  print(x)
  x <- x + 1
}

Using break and next

The break statement exits a loop early, while next skips to the next iteration.

for (i in 1:5) {
  if (i == 3) {
    next # Skips 3
  }
  print(i)
}

Combining Multiple Conditions

You can combine multiple conditions using & (AND) and | (OR).

x <- 10
if (x > 5 & x < 15) {
  print('x is between 5 and 15')
}

Summary

In this lesson, you learned:

• How to use if and if-else statements.
• How to work with loops like for and while.
• How to use break and next for flow control.