/Average2.java 2 Average2.java /class average program with sentinel-controlled repetition. /Java core packages 5 import java.text.DecimalFormat; 6 7 /Java extension packages 8 import javax.swing.JOptionPane; 9 10 public class Average2 11 12 /main method begins execution of Java application 13 public static void main(String args[] 14 15 int gradeCounter, /number of grades entered 16 gradevalue, /grade value 17 total; /sum of grades 18 double average; /average of all grades 19 string input; /grade typed by user 20 21 /Initialization phase 22 total=0; //clear total 23 gradeCounter =0;//prepare to loop 24 25 /Processing phase 26 /prompt for input and read grade from user 27 input JOptionPane.showInputDialog( 28 "Enter Integer Grade,-1 to Quit:"); 29 30 /convert grade from a string to an integer 31 gradevalue Integer.parseInt(input ) 3 ©2006计算机系杨厚群 All rights lefts reserved. ©2006 计算机系 杨厚群 All rights & lefts reserved. 1 // Average2.java 2 // Class average program with sentinel-controlled repetition. 3 4 // Java core packages 5 import java.text.DecimalFormat; 6 7 // Java extension packages 8 import javax.swing.JOptionPane; 9 10 public class Average2 { 11 12 // main method begins execution of Java application 13 public static void main( String args[] ) 14 { 15 int gradeCounter, // number of grades entered 16 gradeValue, // grade value 17 total; // sum of grades 18 double average; // average of all grades 19 String input; // grade typed by user 20 21 // Initialization phase 22 total = 0; // clear total 23 gradeCounter = 0; // prepare to loop 24 25 // Processing phase 26 // prompt for input and read grade from user 27 input = JOptionPane.showInputDialog( 28 "Enter Integer Grade, -1 to Quit:" ); 29 30 // convert grade from a String to an integer 31 gradeValue = Integer.parseInt( input ); 32 Average2.java