Menu
×
   ❮     
HTML CSS JAVASCRIPT SQL PYTHON JAVA PHP HOW TO W3.CSS C C++ C# BOOTSTRAP REACT MYSQL JQUERY EXCEL XML DJANGO NUMPY PANDAS NODEJS R TYPESCRIPT ANGULAR GIT POSTGRESQL MONGODB ASP AI GO KOTLIN SASS VUE DSA GEN AI SCIPY AWS CYBERSECURITY DATA SCIENCE
     ❯   

R If ... Else


Conditions and If Statements

R supports the usual logical conditions from mathematics:

Operator Name Example Try it
== Equal x == y Try it »
!= Not equal x != y Try it »
> Greater than x > y Try it »
< Less than x < y Try it »
>= Greater than or equal to x >= y Try it »
<= Less than or equal to x <= y Try it »

These conditions can be used in several ways, most commonly in "if statements" and loops.


The if Statement

An "if statement" is written with the if keyword, and it is used to specify a block of code to be executed if a condition is TRUE:

Example

a <- 33
b <- 200

if (b > a) {
  print("b is greater than a")
}
Try it Yourself »

In this example we use two variables, a and b, which are used as a part of the if statement to test whether b is greater than a. As a is 33, and b is 200, we know that 200 is greater than 33, and so we print to screen that "b is greater than a".

R uses curly brackets { } to define the scope in the code.


Else If

The else if keyword is R's way of saying "if the previous conditions were not true, then try this condition":

Example

a <- 33
b <- 33

if (b > a) {
  print("b is greater than a")
} else if (a == b) {
  print ("a and b are equal")
}
Try it Yourself »

In this example a is equal to b, so the first condition is not true, but the else if condition is true, so we print to screen that "a and b are equal".

You can use as many else if statements as you want in R.


If Else

The else keyword catches anything which isn't caught by the preceding conditions:

Example

a <- 200
b <- 33

if (b > a) {
  print("b is greater than a")
} else if (a == b) {
  print("a and b are equal")
} else {
  print("a is greater than b")
}
Try it Yourself »

In this example, a is greater than b, so the first condition is not true, also the else if condition is not true, so we go to the else condition and print to screen that "a is greater than b".

You can also use else without else if:

Example

a <- 200
b <- 33

if (b > a) {
  print("b is greater than a")
} else {
  print("b is not greater than a")
}
Try it Yourself »


×

Contact Sales

If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail:
sales@w3schools.com

Report Error

If you want to report an error, or if you want to make a suggestion, send us an e-mail:
help@w3schools.com

W3Schools is optimized for learning and training. Examples might be simplified to improve reading and learning. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. While using W3Schools, you agree to have read and accepted our terms of use, cookie and privacy policy.

Copyright 1999-2024 by Refsnes Data. All Rights Reserved. W3Schools is Powered by W3.CSS.