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LISTING 9.2 MANIPULATING DATA BY USING POINTERS

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 1:    // Listing 9.2 Using pointers
 2:
 3:    #include <iostream.h>
 4:
 5:    int main()
 6:    {
 7:       int myAge;         // a variable
 8:       int * pAge = 0;    // a pointer
 9:      myAge = 5;
10:      cout << myAge:  << myAge << \n;
11:
12:      pAge = &myAge;    // assign address of myAge to pAge
13:
14:      cout << *pAge:  << *pAge << \n\n;
15:
16:      cout << *pAge = 7\n;
17:
18:      *pAge = 7;         // sets myAge to 7
19:
20:      cout << *pAge:  << *pAge << \n;
21:      cout << myAge:  << myAge << \n\n;
22:
23:
24:      cout << myAge = 9\n;
25:
26:      myAge = 9;
27:
28:      cout << myAge:  << myAge << \n;
29:      cout << *pAge:  << *pAge << \n;
30:
31:      return 0;
32:   }

Output:
myAge: 5
*pAge: 5

*pAge = 7
*pAge: 7
myAge: 7

myAge =9
myAge: 9
*pAge: 9
Analysis: This program declares two variables: an int, myAge; and a pointer pAge, which is a pointer to int and which holds the address of myAge. myAge is assigned the value 5 in line 9; this is verified by the printout in line 10.

 
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