#include <iostream>

#include <string>

using namespace std;

void using_extern();

string name;

int main()

{

using_extern();

return 0;

}

#include <iostream>

#include <string>

using namespace std;

extern string name;

extern void using_extern()

{

name="Learning C++ in channel @Learncpp";

cout<<name;

}

#include <iostream>
#include <string>
using namespace std;

void add_number(int num1,int num2);

int main()
{
int num1=1,num2=2;
add_number(num1,num2);
cout<<endl;
cout<<"original num1 is : "<<num1<<endl;
cout<<"original num2 is : "<<num2<<endl;
return 0;
}

void add_number(int num1, int num2)
{
num1=num1+2;
num2=num2+2;
cout<<"num1 is : "<<num1<<endl;
cout<<"num2 is : "<<num2<<endl;
}

#include <iostream>

#include <string>

using namespace std;

void show(string course);

void show(string course, int unit);

void show(string course, int unit, int score);

int main()

{

show("Riazi");

cout<<endl;

show("Riazi", 2);

cout<<endl;

show("Riazi", 2, 18);

cout<<endl;

return 0;

}

void show(string course)

{

cout<<"course name is : "<<course<<endl;

}

void show(string course, int unit)

{

cout<<"course name is : "<<course<<endl;

cout<<"The number of units of  "<<course<<" is : "<<unit<<endl;

}

void show(string course, int unit, int score)

{

cout<<"course name is : "<<course<<endl;

cout<<"The number of units of  "<<course<<" is : "<<unit<<endl;

cout<<"The course grade "<<course<< " is : "<<score<<endl;

}

#include <iostream>
#include <string>
using namespace std;

template <class T1,class T2>
void show(T1 num1, T2 num2)
{
cout<<"num1 is : "<<num1<<endl;
cout<<"num2 is : "<<num2<<endl;
}

int main()
{
show("C++", "Learncpp");
show(40, 30.2);
show('C', "++");
return 0;
}