/******* Defining a function ********/

/*** Function with no return types ***/
function_name(){
    // Statement to execute
}
// OR
void functionn_name(){
    // Statement to execute
}

/*** Function with return types ***/
return_type function_name(){
   // Statement to execute
   return value;
}
// Example :
int calculate_sum(a, b){
  return a + b;
}


/******* Executing a function ********/
function_name();
int sum = calculate_sum(2,2);