How to add a named vector as a row to a data frame, reordered according to column name order?

Question

How to add a named vector to a data frame, with the components of the vector reordered according to the column names of the data frame?

I need to build a data frame

Answer 1

Make a data frame out of v2 prior to the rbind:

rbind(df, as.data.frame(t(v2)))
##   id va vb vc
## 1  1 11 21 31
## 2  2 12 22 32
## 3  4 14 25 NA
## 4  9 19 NA 34

Here is why this works:

v2 has names, but it acts like a column vector to as.data.frame:

as.data.frame(v2)
##    v2
## va 19
## id  9
## vc 34
## vb NA

Thus, you must transpose the data to put it into the correct form:

as.data.frame(t(v2))
##   va id vc vb
## 1 19  9 34 NA