x#i
If x is a list, x#i returns the ith element of x. The entries of the list are numbered starting with 0. If i is negative, then the entries are numbered ending with 1. If i is out of range, an error is signaled.



If x is a hash table or database, x#i provides the value associated with the key i.



If x is a string, x#i provides the ith character of x, if there is one. Negative indices are counted backward from the end, as with lists. If i is out of range, an error is thrown.



Assignment to x#i can change x if x is mutable.



