rindex (x, s)
The rindex(x,s) function searches for the last occurrence of the string s in x.
It returns the offset of the first character of the last occurrence or 0 if the string s did not occur in x.
The search is case-insensitive.
This function returns a value of type Number.
Examples
rindex ("abcdabcd", "cd")
Result: 7.
rindex ("AbCdaBcD", "cd")
Result: 7. Note that the search is case-insensitive.