R Error : invalid (NULL) left side of assignment (2 Examples)

In this R tutorial you’ll learn how to fix the “Error in X : invalid (NULL) left side of assignment”.

The article will consist of the following content blocks:

You’re here for the answer, so let’s get straight to the examples!

Example 1: Replicate the Error in X : invalid (NULL) left side of assignment

The following syntax explains how to reproduce the “Error in X : invalid (NULL) left side of assignment” in the R programming language.

Let’s assume that we want to assign a value to a new data object. Then, we might try to use the following R code:

sum() <- 7                     # Try to assign value
# Error in sum() <- 7 : invalid (NULL) left side of assignment

As you can see, the execution of the previous R syntax lead to the “Error in X : invalid (NULL) left side of assignment”.

The reason for this is that it’s not possible to assign a value to a function.

Next, I’ll show how to deal with with problem!

Example 2: Resolve the Error in X : invalid (NULL) left side of assignment

The R syntax below explains how to handle the “Error in X : invalid (NULL) left side of assignment”.

For this, we have to specify a valid data object name to which we assign our value:

x <- 7                         # Properly assign value
x                              # Print data object
# [1] 7

The previous code has assigned the value 7 to the data object x. Looks good!

Video, Further Resources & Summary

If you need further information on the R programming code of the present post, you may have a look at the following video on my YouTube channel. In the video, I demonstrate the R programming codes of this article in RStudio:

The YouTube video will be added soon.

In addition, you may have a look at some of the related articles on my website:

• Error in file(file, “rt”) : invalid ‘description’ argument (read.table & csv)
• How to Fix the R Error in stripchart.default(x1, …) : invalid plotting method
• Error in .subset(x, j) : invalid subscript type ‘list’
• Handling Errors & Warnings in R
• The R Programming Language

In summary: At this point you should know how to resolve the “Error in X : invalid (NULL) left side of assignment” in R programming. Don’t hesitate to let me know in the comments, if you have additional questions or comments. In addition, don’t forget to subscribe to my email newsletter to receive updates on new articles.