Check if Number is Integer in R (3 Examples)

In this R tutorial you’ll learn how to test whether a number is an integer (i.e. a whole number).

Table of contents:

• Example Data
• Example 1: Check if Number is Integer with round Function
• Example 2: Check if Number is Integer with %% Operator
• Example 3: Check if Number is Integer with all.equal Function
• Video, Further Resources & Summary

Let’s get started.

Example Data

First, let’s create a data object called x, which is containing an integer value (i.e. 5):

x <- 5                               # Create integer object

Now you might say: Easy going, I’m simply using the is.integer function:

is.integer(x)                        # Apply is.integer function
# FALSE

Be careful! As you can see, the is.integer function is returning the logical value FALSE to the RStudio console, even though our value x is obviously an integer.

The reason for that can be found in the R help documentation of the is.integer function:

is.integer(x) does not test if x contains integer numbers! For that, use round, as in the function is.wholenumber(x) in the examples.

The reason for that is that the is.integer function is checking whether a data object has the integer class (or data type). Since our data object has the numeric data class, the is.integer function returns FALSE.

In the following examples, I’ll show how to check for whole numbers properly.

Example 1: Check if Number is Integer with round Function

Example 1 tests for integer numbers using the round function:

x == round(x)                        # Check for integer with round function
# TRUE

The RStudio console returns the logical value TRUE, i.e. our data object x is an integer.

Example 2: Check if Number is Integer with %% Operator

We can also use the %% operator to check if our number is an integer:

x %% 1 == 0                          # Check for integer with %% operator
# TRUE

Example 3: Check if Number is Integer with all.equal Function

The third solution I want to show you is based on the all.equal function. Again, the RStudio console output is TRUE:

all.equal(x, as.integer(x))          # Check for integer with all.equal function
# TRUE

Video, Further Resources & Summary

I have recently published a video tutorial on my YouTube channel, which explains the R programming codes of this article. You can find the video below.

Furthermore, you could have a look at the related articles that I have published on this website. You can find a selection of posts here.

• Rounding Data in R
• The R Programming Language

This article illustrated how to test if a value or a vector of values contains whole numbers in the R programming language. Let me know in the comments below, if you have additional questions.