Convert from lowercase to uppercase all values in all character variables in dataframe

Question

I have a mixed dataframe of character and numeric variables.

city,hs_cd,sl_no,col_01,col_02,col_03
Austin,1,2,,46,Female
Austin,1,3,,32,Male
Austin,1,4,,27,         


        

Answer 1

It simple with apply function in R

f <- apply(f,2,toupper)

No need to check if the column is character or any other type.