This functionality is only available for certain module packages.

lastIndexOf(String sub)

Delivers the position of the last occurrence of the character string sub in the original. If the character string sub is not contained in the original the return value is: -1.

lastIndexOf(String sub)
Argument String sub
Return value Integer New position of the last occurrence of the character string sub in the original. If the character string sub is not contained in the original the return value is: -1.