How to show classes of all columns of a data frame?

Hi all,

Suppose I have a data frame myDF, col A is factor, col B is numeric, col C
is character. I can get their classes by

class(myDF$A)

but is there a quick way to show what classes of all columns are? Thank you.

Tian

Depending upon the output format you desire:

lapply(iris, class)

$Sepal.Length
[1] "numeric"

$Sepal.Width
[1] "numeric"

$Petal.Length
[1] "numeric"

$Petal.Width
[1] "numeric"

$Species
[1] "factor"


or

sapply(iris, class)

Sepal.Length  Sepal.Width Petal.Length  Petal.Width      Species
   "numeric"    "numeric"    "numeric"    "numeric"     "factor"


See ?lapply and ?sapply


HTH,

Marc Schwartz