Example of Program using passing by value and use of arguments in a function

note that the numbers are not part of the program, they are used for you to tract the flow 
 

11 // function example, passing by values and void functions 22 #include <iostream> 33 #include<string> 44 using namespace std; 55 // function prototypes inserted here because  //they are used before they are defined 66  void PrintFunction(void); 77 double DFunction(); 88 int IntFunction(int,int); 99 void myName(string); 1010  // main program... 1111 int main() 1212 { 1313 cout<<"Function PrintFunction () displays.."<<endl; 1414 // call, to the void PrintFunction () 1515 PrintFunction (); 1616 cout<<" \nWorking with function DFunction..."<<endl; 1717 // calling function DFunction of type double but without any argument... 1818 double d = DFunction(); 1919 // display the value returned by DFunction. 2020 cout<<"The value returned by DFunction= "<<d<<endl; 2121 int y = 100; 2222 int x=2; 2323 2424 //Calling function IntFunction of type int and with an argument... 2525 int z = IntFunction(x, y); 2626 cout<<"Function IntFunction calculates the recieved and  returns the result main() "<<endl; 2727 // display the returned value... 2828 cout<<"The value returned by IntFunction is = "<<z<<endl; 2929 string Name="Selina"; 3030 myName(Name); 3131 // return 0 if everything was successful 3232 return 0;//end main

3333 } 3434 void PrintFunction () 3535 { 3636 // Simply display the following text when called. //return no value to the caller 3737 cout<<"\nWhen PrintFunction is called "<<endl; 3838 cout<<"It returns nothing because it of a void function.  However this message is displayed once it is called"<<endl; 3939 } 4040 // When called function DFunction() receives nothing .  // It will however return a value it will calculate basing on its local variables 4141 double DFunction() 4242 { 4343 double p = 12.122; 4444 double q=2.0; 4545 cout<<"\nAlthough function DFunction does not receive data when called " 4646 <<"\nIt returns a value" 4747 <<"\nto the calling function..."<<endl; 4848 // return the result to the caller... 4949 return p/p; 5050 } 5151 int IntFunction(int a,int b) 5252 { 5353 // receive data, works on it and returns the result to the caller 5454 a=2; 5555 b = a * 100; 5656 int c=b/4; 5757 cout<<"On completing the calculation function it.. " 5858 <<"\nreturns result to the calling function  which in is this case is main()\n"<<endl; 5959 // now return the data stored in c to main () 6060 return c; 6161 } 6262 // Function myName receives the names and displays on the screen instead of returning a value 6363 void myName(string fname) 6464 { 6565 // receive something but return nothing... 6666 string firstName = fname; 6767 cout<<"\nFunction myName receives the name from the caller."<<endl; 6868 cout<<"but does not return any value to the caller, rather..."<<endl; 6969 cout<<"Then it processes and displays name as "<<firstName<<endl; 7070 }

Output: Function PrintFunction () displays.. When PrintFunction is called It returns nothing because it of a void function. However this message is displayed once it is called Working with function DFunction... Although function DFunction does not receive data when called It returns a value to the calling function... The value returned by DFunction= 1 On completing the calculation function it.. returns result to the calling function which in is this case is main() Function IntFunction calculates the recieved and returns the result main() The value returned by IntFunction is = 50 Function myName receives the name from the caller. but does not return any value to the caller, rather... Then it processes and displays name as Selina

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