function Pos(Substr: string; S: string): Integer;
In Delphi, Pos searches for a substring, Substr, in a string, S. Substr and S are string-type expressions.
Pos searches for Substr within S and returns an integer value that is the index of the first character of Substr within S. Pos is case-sensitive. If Substr is not found, Pos returns zero.
The PosEx function is similar to Pos, but provides additional features and can be used in C++ code.