Inline Functions in C++

Inline functions are small functions defined with the inline keyword. The advantage of using inline functions are –

  • They do not involve the usual stack operations as with ordinary function calls and returns, thus speeds up execution
  • Usually used within classes which involves a lot of operations (small) on the private data
  • It is professional to define the inline functions within their class declarations. In this case, all such member functions are automatically inline irrespective of the declaration inline.

An example C++ program using inline functions is shown below –

//inline1.cpp
#include <iostream>
#include <string>
using namespace std;
class sum{
       int a,b;
       public:
           void set_num(int i, int j){
              a=i; 
              b=j;
           }
           int get_sum(){
               return(a+b);
           }
};

main(){
     sum s;
     int k,l;
   
     cin >> k >> l;
     s.set_num(k,l);

     cout << "Sum is>>";
     cout <<  s.get_sum();
     return 0;
}

Output:

2 
4                                                                                                                                                      
Sum is>>6