The function overload is different, and the example expression of the function overload is as follows: Function foo (i: integer): string; overload; function foo (s: string): string; overload; pass different parameters, Select Perform different functions.
The polymorphism is to give the child object to the parent class object (big inverse?! :)), let the parent class object have a sub-object method, an example expression is as follows: tparent = class (TOBJECT) Procedure Draw; Virtual; End ;
TCHILD = Class (Tparent) Procedure Draw; Override; Virtual;
Parent: = CHILD;
Parent.draw; // Execute subclass DRAW;
That is why we always see the parameters of Sender: Tobject, which is the result of assigning subclass objects such as 1 Button to the Parent class (TOBJECT)
