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  1. // This program uses reference variables as function parameters.
  2. #include <iostream>
  3. using namespace std;
  4.  
  5. // Function prototypes. Both functions use reference variables
  6. // as parameters.
  7. void doubleNum(int &);
  8. void getNum(int &);
  9.  
  10. int main()
  11. {
  12.     int value;
  13.  
  14.     // Get a number and store it in value.
  15.     getNum(value);
  16.  
  17.     // Double the number stored in value.
  18.     doubleNum(value);
  19.  
  20.     // Display the resulting number.
  21.     cout << "That value doubled is " << value << endl;
  22.     return 0;
  23. }
  24.  
  25. //***************************************************************
  26. // Definition of getNum.                                         *
  27. // The parameter userNum is a reference variable. The user is    *
  28. // asked to enter a number, which is stored in userNum.          *
  29. //***************************************************************
  30. void getNum(int &userNum)
  31. {
  32.     cout << "Enter a number: ";
  33.     cin >> userNum;
  34. }
  35.  
  36. //***************************************************************
  37. // Definition of doubleNum.                                      *
  38. // The parameter refVar is a reference variable. The value in    *
  39. // refVar is doubled.                                            *
  40. //***************************************************************
  41. void doubleNum(int &refVar)
  42. {
  43.     refVar *= 2;
  44. }
  45.  
Success #stdin #stdout 0.01s 5312KB
comments (?)
stdin 
12
stdout 
Enter a number: That value doubled is 24
https://ideone.com/TdtnPt
language:
C++ (gcc 8.3)
created:
18 hours ago
visibility:
public

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