Sort an array of numbers in descending order

Write a function that takes an array of numbers as argument. It should return an array with the numbers sorted in descending order.
function
myFunction
(
arr
)
{

return
}
Test Cases:
myFunction([1,3,2])
Expected
[3,2,1]
myFunction([4,2,3,1])
Expected
[4,3,2,1]