New to R, receive an error in my function

Question

x <- c(2.2, 7.8, -4.4, 0.0, -1.2, 3.9, 4.9, 2.0, -5.7, -7.9, -4.9,  28.7,  4.9)

q<-function(x){
    bound<-quantile(x)
    iqr<-bound[4]-bound[2]
    re