A function is block of code which is used to perform a particular task, for example let’s say you are writing a large C++ program and in that program you want to do a particular task several number of times, like displaying value from 1 to 10, in order to do that you have to write few lines of code and you need to repeat these lines every time you display values. Another way of doing this is that you write these lines inside a function and call that function every time you want to display values. This would make you code simple, readable and reusable.
#include<iostream.h>
#include<conio.h>
void sum();
int a=3,b=7,c;
void sum()
{
c=a+b;
cout<<"Sum:"<<c;
}
void main()
{
clrscr();
sum();
getch();
}
Sum:10