1. To define a function outside the class, there MUST be a prototype inside the class. For eg. class Jg{ int num; public: Jg(){ num=0; } }; void Jg::Display() //Error will be here { cout<<num; } //This Program will give the error "no 'void Jg::Display()' member function declared in class 'Jg'" 2. What if one member function defined twice, once inside class and once outside? Will give error "[error]redefintion of int Jg::Display()" And then pointing on the first defintion it will give "[NOTE] int Jg::Display() previously defined here" PROGRAM - #include<iostream> using namespace std; class Jg{ int num; public: Jg(){ num=0; } Display(){ cout<<"Hello"; } }; int Jg::Display(){ //ERROR cout<<num; } main(){ Jg J1; J1.Display(); } 3. What if a member function declared twice inside the class? Will show error "int Ag::Display() cannot be overloaded...