x<-data.frame(apple=c(1,4,2,3),pear=c(4,8,5,2))
x
# apple pear
# 1 1 4
# 2 4 8
# 3 2 5
# 4 3 2
x$banana<-c(9,5,6,2)
x
# apple pear banana
# 1 1 4 9
# 2 4 8 5
# 3 2 5 6
# 4 3 2 2
