Counting the number of elements with the values of x in a vector

Question

I have a vector of numbers:

numbers <- c(4,23,4,23,5,43,54,56,657,67,67,435,
         453,435,324,34,456,56,567,65,34,435)

How can I hav

Answer 1

The most direct way is sum(numbers == x).

numbers == x creates a logical vector which is TRUE at every location that x occurs, and when suming, the logical vector is coerced to numeric which converts TRUE to 1 and FALSE to 0.

However, note that for floating point numbers it's better to use something like: sum(abs(numbers - x) < 1e-6).