R error message: invalid type (NULL) for variable when running t test [closed]

Hi I am currently trying to perform a t-test for BMI and the Outcome variables in a diabetes dataset I am working on.

My goal is to determine whether there is a significant difference between the means of two groups.

So far I’ve tried looking for any NULL values within my data set and these variables using summary(diabetes) and sum($BMI)), and cannot seem to find any.

So far my code is:

diabetes <- t.test(diabetes$BMI ~ diabetes$Outcome)

Any help is greatly appreciated, thank you.

EDIT: okay so I realized what I was doing wrong. I was feeding the t.test back into my main data set (diabetes) and calling it as diabetes. when I print(diabetes) alone a welch two sample t-test actually comes out for the variables I selected! I am also using the Pima Indians diabetes dataset from kaggle (

Also, I believe after the first time running
diabetes <- t.test(diabetes$BMI ~ diabetes$Outcome) over again
was the reason why the error:
Error in model.frame.default(formula = diabetes$BMI ~ diabetes$Outcome) :
invalid type (NULL) for variable ‘diabetes$BMI’
was appearing since the first time I ran diabetes <- t.test(diabetes$BMI ~ diabetes$Outcome) actually came out with no error, but I failed to remember to print(diabetes) since that was where I fed it into.

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