R: convert list of numbers from character to numeric

Question

I have a column in my dataframe where in every cell there are one or more numbers. If there are many numbers, they are seperated with a space. Furthermore, R considers them as a

Answer 1

We can use scan

sum(scan(text=str1, what=numeric(), quiet=TRUE))
#[1] 421

data

str1 <- "6 310 21 20 64"