I have two strings that start with the same characters, but at some
unknown and varying point they begin to differ. I want the position
number of the first non-matching character.

For example:
-- table and chair
-- table plus chair
-- position of first non-matching character is 7 (the "a" in
"and", and the "p" in "plus").

In the above example, both strings start out "table ", then start to
differ beginning with the 7th character. How can I return the position
of the first non-matching character, which in this example is 7?


Thanks,

Greg