How does the table and $freq function work in R - r

Question

I want a function for the mode of a vector. Abhiroop Sarkar's answer to This question works, but I want to understand why.
Here is the code
Mode <- function(x){
y <- data.frame(table(x))
y[y$Freq == max(y$Freq),1]
}
1) Wy do we need to put the table in a data frame,
2) in this line
y[y$Freq == max(y$Freq),1]
what does the y$Freq do? is frequency a default columns in the table?

Answer 1

When we convert a table output to data.frame, it creates a two column data.frame
set.seed(24)
v1 <- table(sample(1:5, 100, replace = TRUE))
y <- data.frame(v1)
y
# Var1 Freq
#1 1 19
#2 2 24
#3 3 22
#4 4 16
#5 5 19
The first column 'Var1' is the names of the frequency output from table and the 'Freq' is the actual frequency of those names
y[y$Freq == max(y$Freq), 1]
#[1] 2
#Levels: 1 2 3 4 5
Now, we are subsetting the first column 'Var1' based on the max value of 'Freq', and it returns a vector because of the drop = TRUE in [ when there is a single column
If we want to return a data.frame with single, add drop = FALSE at the end
y[y$Freq == max(y$Freq), 1, drop = FALSE]
# Var1
#2 2
Regarding the default name Freq, it is created from the as.data.frame.table method
as.data.frame.table
function (x, row.names = NULL, ..., responseName = "Freq", stringsAsFactors = TRUE,
sep = "", base = list(LETTERS))
{
ex <- quote(data.frame(do.call("expand.grid", c(dimnames(provideDimnames(x,
sep = sep, base = base)), KEEP.OUT.ATTRS = FALSE, stringsAsFactors = stringsAsFactors)),
Freq = c(x), row.names = row.names))
names(ex)[3L] <- responseName
eval(ex)
}