The transform function (y) takes two strings as
arguments. It turns each instance of the first character in string 1
into the first character in string 2, then the second character in
string 1 into the second character in string 2, and so on. In the
following example, ``a'' is transformed into ``A'', irrespective of
whether it is followed by ``b'':
y/abcde/ABCDE/
The components of the two strings are literals, and the
transformation performed depends on position. As with the substitute
command, y takes an optional address as an argument:
15y/abcde/ABCDE/