Using combn() in R to find all possible t-test relationships, how to access the variables compared?

So, I have a DataFrame with a large number of variables, and I want to cross-check each variable with each other variable with a t-test.

A sample of my data, called trust_news:

Then, I run this code on it:

trust_news_combos <- combn(trust_news, 1, t.test, simplify = TRUE)

First off, is the code correct? I have no clue what to put for m in the combn() function. AAnyway, that line gives me this:

It gives me the p-values I'm looking for in row 3, but how do I check which two columns are being checked?

Any help is appreciated and will be thanked in my final code!

You should write a small function to compute exactly what you need, and use it instead of the standard function t.test. For example:

# get four column names
cols <- names(mtcars)[1:4]   # use trust_news instead of mtcars, and keep all the names

# compute the pval for a pair of names
pval <- function(pair) {
  value <- t.test(mtcars[, pair[1]], mtcars[, pair[2]])$p.value
  names(value) <- paste(pair, collapse = " vs. ")
  value
}

# do it for all pairs.  Don't simplify, and it will keep the names
combn(cols, 2, pval, simplify = FALSE)
#> [[1]]
#>  mpg vs. cyl 
#> 9.507708e-15 
#> 
#> [[2]]
#> mpg vs. disp 
#> 7.978234e-11 
#> 
#> [[3]]
#>   mpg vs. hp 
#> 1.030354e-11 
#> 
#> [[4]]
#> cyl vs. disp 
#> 1.774454e-11 
#> 
#> [[5]]
#>   cyl vs. hp 
#> 8.321996e-13 
#> 
#> [[6]]
#> disp vs. hp 
#> 0.001545647

^{Created on 2021-05-22 by the reprex package (v2.0.0)}