Check if Column Exists in Data Frame in R (Example)

In this R tutorial you’ll learn how to inspect whether a variable exists in a data frame.

Table of contents:

• Example Data
• Example: Search for Column Name in Data Frame
• Video, Further Resources & Summary

Sound good? Let’s jump right to the examples:

Example Data

In the example of this R tutorial, we’ll use the following data frame as basement:

data <- data.frame(col1 = 1:5,              # Create example data
                   col2 = letters[1:5],
                   col3 = 3)
data                                        # Inspect example data
#   col1 col2 col3
# 1    1    a    3
# 2    2    b    3
# 3    3    c    3
# 4    4    d    3
# 5    5    e    3

Our example data contains five rows and three columns. The variables are called col1, col2, and col3.

Example: Search for Column Name in Data Frame

If we want to find a variable in a data frame, we can use a combination of the %in%-operator and the colnames function:

"col3" %in% colnames(data)                  # Check if column exists
# TRUE

As you can see, the previous R code returned the logical value TRUE to the RStudio console. This means that the column name “col3” exists in our data frame.

Let’s check another column name:

"other_col" %in% colnames(data)             # Column does not exist
# FALSE

The RStudio console returns FALSE, i.e. the variable “other_col” is not existing in our data matrix.

Video, Further Resources & Summary

I have recently published a video on the Statistics Globe YouTube channel, which explains the content of this tutorial. You can find the video below.

Furthermore, you might want to have a look at some of the other tutorials of my website. You can find a selection of other tutorials below.

• Rename a Column Name in R
• Pass Data Frame Column Name to Function
• The R Programming Language

Summary: At this point you should have learned how to look for certain column names in a data matrix in the R programming language. If you have any additional comments and/or questions, let me know in the comments section.