The following example (Fig. 2.10) uses six if
statements to compare two numbers input by the user. If the condition in any of these if
statements is satisfied, the output statement associated with that if
statement is executed.
1 // Fig. 2.13: fig02_13.cpp
2 // Comparing integers using if statements, relational operators
3 // and equality operators.
4 #include <iostream> // allows program to perform input and output
5
6 using std::cout; // program uses cout
7 using std::cin; // program uses cin
8 using std::endl; // program uses endl
9
10 // function main begins program execution
11 int main()
12 {
13 int number1 = 0; // first integer to compare (initialized to 0)
14 int number2 = 0; // second integer to compare (initialized to 0)
15
16 cout << "Enter two integers to compare: "; // prompt user for data
17 cin >> number1 >> number2; // read two integers from user
18
19 if ( number1 == number2 )
20 cout << number1 << " == " << number2 << endl;
21
22 if ( number1 != number2 )
23 cout << number1 << " != " << number2 << endl;
24
25 if ( number1 < number2 )
26 cout << number1 << " < " << number2 << endl;
27
28 if ( number1 > number2 )
29 cout << number1 << " > " << number2 << endl;
30
31 if ( number1 <= number2 )
32 cout << number1 << " <= " << number2 << endl;
33
34 if ( number1 >= number2 )
35 cout << number1 << " >= " << number2 << endl;
36 } // end function main
Enter two integers to compare: 3 7
3 != 7
3 < 7
3 <= 7
Enter two integers to compare: 22 12
22 != 12
22 > 12
22 >= 12
Enter two integers to compare: 7 7
7 == 7
7 <= 7
7 >= 7