R: fill down multiple columns

Question

I'm using fill() from the tidyr package. fill(df, colname1, colname2, colname3) works fine, until I found a dataset with 32 variables. How should I fill down all columns without typing each name?

I've tried:

fill(df,colnames(df)),
fill(df,1:32), 
fill(df,colname1:colname32). 

and produced the following errors:

Error: All select() inputs must resolve to integer column positions.
The following do not:
*  colnames(df1)

Error: tinyformat: Not enough conversion specifiers in format string

Error: tinyformat: Not enough conversion specifiers in format string

Answer 1

Another alternative with package zoo which can also fill backwards if desired. On the sample created above-

zoo::na.locf(df)

   col1 col2 col3
1     2    4    e
2     2    4    e
3     3    4    a
4     2    4    b
5     1    3    d
6     2    4    d
7     2    1    b
8     1    1    e
9     3    3    e
10    1    2    e
11    1    4    e
12    1    1    e
13    3    1    a
14    3    4    c
15    3    3    b
16    2    3    e
17    3    1    e
18    3    2    b
19    3    5    c
20    3    5    e

where df is

   col1 col2 col3
1     2    4    e
2     2   NA    e
3     3    4    a
4     2    4    b
5     1    3    d
6     2    4 <NA>
7    NA    1    b
8     1   NA    e
9     3    3 <NA>
10    1    2    e
11    1    4    e
12   NA    1 <NA>
13    3   NA    a
14   NA    4    c
15    3    3    b
16    2    3    e
17    3    1    e
18   NA    2    b
19   NA    5    c
20    3    5    e

Answer 2

Building off @akrun's comment and data, here are two other ways using the tidyr:

Data

set.seed(24)
df <- data.frame(col1= sample(c(NA, 1:3), 20, replace=TRUE), 
                 col2 = sample(c(NA, 1:5), 20, replace=TRUE),
                 col3 = sample(c(NA, letters[1:5]), 20, replace=TRUE),
                 stringsAsFactors=FALSE)

Two Options

#Specify column names
fill(df, c("col1", "col2"), .direction = "down")

#Specify range of columns
fill(df, c(col1:col3), .direction = "down")