Adds all the elements of a typed array into a string, separated by the specified separator string.
join(separator)
separator
A string used to separate one element of the array from the next in the resulting string. If omitted, the array elements are separated with a comma.
A string.
new Uint8Array([1, 2, 3]).join()
"1,2,3"
new Uint8Array([1, 2, 3]).join(", ")
"1, 2, 3"