top of page

If else Statements

You're currently learning a lecture from the course: 


Prerequisite Terminologies

In order to have thorough understanding of the main topic, you should have the basic concept of the following terms:

Introduction to R language




Yusra Karim


Decision making is an important part of programming. This can be achieved in R programming utilizing the ‘If Else’ statements. ‘If Else’ statements are the conditional statements that can be utilized to return an output based on a condition. It allows you to run logical conditions, statements or anything that is correlated with the logic.

  • If Statement:

The syntax of if statement is:

If (expression) {



Here how this works, if the expression provided within the brackets is TRUE, the statement within curly brackets will be executed. But if it’s FALSE, nothing will happen. Here the expression can be a logical or numeric vector.

  • If Else Statement:

The syntax of ‘if else’ statement is:

If (expression) {


} else {



The else part is optional that particularly provides an extension to the if else statement and is only executed when the expression provided after the ‘if’ keyword is FALSE.


  • For the understanding of if else statements, we’ll use an example to retrieve and read a particular file from the working directory. You can utilize if else statement as:


if (file.exists(“filename”)) {

myData <- read (“filename”)

View (myData)

} else {

Print (“No such file, please create it.”)


[If the file exists in the working directory then the if condition will TRUE, so the if statement will be executed and it’ll print out that particular file.

But if the file does not exist, the if condition will  be FALSE then the else statement will be executed and it’ll print out “No such file, please create it”.]


In this video, we learned about the if else statements and how these conditional statements can be  utilized in R programming.

File(s) Section

If a particular file is required for this video, and was discussed in the lecture, you can download it by clicking the button below.

bottom of page