Practice exercise -- Allocating memory                

                          
Storing data into memory:
1. Instruct computer to allocate memory
2. Invoke program statements to put data into allocated memory

Constant: A memory location whose value may not be changed:

   const dataType IDENTIFIER = value; 

Variable: Memory location that may be changed

   dataType identifier1, identifier2, ..., identifierN;

Storing data:
1. Store with an assignment statement:

   identifier = expression;

2. Store through an input statement

   cin >> variable;

Printing (stored) data:

   cout << variable;

Statement                              Show identifier name and value (or error)
--------------------------------       -----------------------------------------
1.  int a,                         |
        b = 2;                     
                                   |
    a = b;  
                                   |
2.  int x = 3, 
        y = 4;                     |

    y + 5 = x * 3;                 |

3.  double inches = 0.0;           |

    inches = 6.0;              
    inches = inches + inches;      |

4.  const int E = 5;               |

5.  double x = -5.5, 
           y = 17.5;               |
    int d = 4;

    y = d - x + y;                 |

6.  int n;                         |

    cin >> n; // 1.23 entered      |

7.  int count = 0;                 |

    cout << count;                 |
    cout << count++;
    cout << ++count;               |