Are dataframe[ ,-1] and dataframe[-1] the same?

Question

Sorry this seems like a really silly question but are dataframe[ ,-1] and dataframe[-1] the same, and does it work for all data types?

And

Answer 1

Sorry, wanted to leave this as a comment but thought it was too big, I just found it interesting that the only one which remains a non integer is dataframe[1].

Further to Carl's answer, it seems dataframe[[1]] is treated as a matrix as well. But dataframe[1] isn't....

But it can't be treated as a matrix cause the results for dataframe[[1]] and matrix[[1]] are different.

D <- as.data.frame(matrix(1:16,4))
D
M <- (matrix(1:16,4))
M
> D[ ,1]        # data frame leaving out first column
[1] 1 2 3 4
> D[[1]]        # first column of dataframe
[1] 1 2 3 4
> D[1]          # First column of dataframe
  V1
1  1
2  2
3  3
4  4
> 
> class(D[ ,1])
[1] "integer"
> class(D[[1]])
[1] "integer"
> class(D[1])
[1] "data.frame"
> 
> M[ ,1]        # matrix leaving out first column
[1] 1 2 3 4
> M[[1]]        # First element of first row & col
[1] 1
> M[1]          # First element of first row & col
[1] 1
> 
> class(M[ ,1])
[1] "integer"
> class(M[[1]])
[1] "integer"
> class(M[1])
[1] "integer"