lecture3-流程控制思考题 #21
Description
以下代码的第３２行可以省略么？为什么？
1
2 // Compare integers using if structures, relational operators
3 // and equality operators.
4
5 // Java extension packages
6 import javax.swing.JOptionPane;
7
8 public class Comparison {
9
10 // main method begins execution of Java application
11 public static void main( String args[] )
12 {
13 String firstNumber; // first string entered by user
14 String secondNumber; // second string entered by user
15 String result; // a string containing the output
16 int number1; // first number to compare
17 int number2; // second number to compare
18
19 // read first number from user as a string
20 firstNumber =
21 JOptionPane.showInputDialog( "Enter first integer:" );
22
23 // read second number from user as a string
24 secondNumber =
25 JOptionPane.showInputDialog( "Enter second integer:" );
26
27 // convert numbers from type String to type int
28 number1 = Integer.parseInt( firstNumber );
29 number2 = Integer.parseInt( secondNumber );
30
31 // initialize result to empty String
32 result = "";
33
34 if ( number1 == number2 )
35 result = number1 + " == " + number2;
36
37 if ( number1 != number2 )
38 result = number1 + " != " + number2;
39
40 if ( number1 < number2 )
41 result = result + "\n" + number1 + " < " + number2;
42
43 if ( number1 > number2 )
44 result = result + "\n" + number1 + " > " + number2;
45
46 if ( number1 <= number2 )
47 result = result + "\n" + number1 + " <= " + number2;
48
49 if ( number1 >= number2 )
50 result = result + "\n" + number1 + " >= " + number2;
51
52 // Display results
53 JOptionPane.showMessageDialog(
54 null, result, "Comparison Results",
55 JOptionPane.INFORMATION_MESSAGE );
56
57 System.exit( 0 ); // terminate application
58
59 } // end method main
60
61 } // end class Comparison