Finding corresponding records of a specific value in a data frame in R

Question

I have the following dataframe:

 sales<-c(1,2,3,45,4,3,21)
 price<-c(35,45,30,10,33,44,15)
 df<-data.frame(sales,price)

I am looking for way to find the corresponding price of the maximum sales as well as its row number and record them as a and b .

For instance here maximum sales is equal to 45. This is when the price is equal to 10 (a should be 10) and this record is on the 4th row (b should be 4).

  > a
 [1] 10
 > b
 [1] 4

Answer 1

you can try

(x <- df[df$sales == max(df$sales), ])
  sales price
4    45    10
a <- x$price
b <- strtoi(row.names(x))

Answer 2

a <- df[which.max(df$sales),][,2]
b <- order(df[,1],decreasing=T)[1]
a
[1] 10
b
[1] 4