Rbind with new columns and data.table

Question

I need to add many large tables to an existing table, so I use rbind with the excellent package data.table. But some of the later tables have more columns than the original

Answer 1

Since v1.9.2, data.table's rbind function gained fill argument. From ?rbind.data.table documentation:

If TRUE fills missing columns with NAs. By default FALSE. When TRUE, use.names has to be TRUE, and all items of the input list has to have non-null column names.

Thus you can do (prior to approx v1.9.6):

data.table::rbind(dt.1, dt.2, fill=TRUE) 
#    aa bb cc
# 1:  1  2 NA
# 2:  2  3 NA
# 3:  3  4 NA
# 4:  1  2  3
# 5:  2  3  4
# 6:  3  4  5

UPDATE for v1.9.6:

This now works directly:

rbind(dt.1, dt.2, fill=TRUE)
#    aa bb cc
# 1:  1  2 NA
# 2:  2  3 NA
# 3:  3  4 NA
# 4:  1  2  3
# 5:  2  3  4
# 6:  3  4  5