Getting lines added up and averaged

[mike statham]

  import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.StringTokenizer;

public class GradesAAA {

public static void main(String[] args) throws IOException   
   {   
      
    String firstName = null, gradeString = null, filename;   
   String strLine;   
    // Initializing new Strings for each range   
    String firstRange = "", secondRange = "", thirdRange = "", fourthRange = "";   
   int grade = 0, linesWithGrades = 0;   
   double avg = 0; 
   
   
      
   filename = ("grades.txt");   
   StringTokenizer st;   
   BufferedReader br;   
    try {   
    br = new BufferedReader(new FileReader(filename)); // Required to read the file   
      
    while ((strLine = br.readLine()) != null) {   
        st = new StringTokenizer(strLine, " ");   
        try {   
            while (st.hasMoreTokens()) {   
                firstName = st.nextToken();  
                
                 
                  
                    gradeString = st.nextToken();   
                    grade = Integer.parseInt(gradeString)/3; 
                    
                    
                      
               if (grade > 0 && grade < 69) {   
                  avg += grade;   
                  linesWithGrades++;   
                        firstRange +=  firstName + "\t" + grade + "\n";   
               } else if (grade > 69 && grade < 80) {   
                  avg += grade;   
                  linesWithGrades++;   
                        secondRange +=  firstName + "\t" + grade + "\n";   
               } else if (grade > 79 && grade < 90) {   
                  avg += grade;   
                  linesWithGrades++;   
                        thirdRange +=  firstName + "\t" + grade + "\n";   
               } else if (grade > 89 && grade < 101) {   
                  avg += grade;   
                  linesWithGrades++;   
                        fourthRange +=  firstName + "\t" + grade + "\n";   
               }   
                    // To avoid adding the wrong data to noData, the variables are cleaned   
                    firstName = "";   
                      
                    gradeString = "";   
         }   
        } catch (Exception e) {   
            // Catches null data for noData   
                
         }   
   }   
                } catch (Exception e) {   
                System.out.println("Exception while reading grades file: " + e);   
            }   
            System.out.println("Students with grades 69 and below: ");   
            System.out.println(firstRange);   
            System.out.println("Students with grades between 70 and 79: ");   
            System.out.println(secondRange);   
            System.out.println("Students with grades between 80 and 89: ");   
            System.out.println(thirdRange);   
            System.out.println("Students with grades of 90 and above: ");   
            System.out.println(fourthRange);   
            System.out.println("Persons with no grade or incomplete data: ");   
               
            System.out.println();   
            System.out.println();   
            System.out.print("The grade point average is" + "\t" + Math.ceil(avg / linesWithGrades));   
            System.out.println();   
   }   
}   
 

Whic prints out this:
Students with grades 69 and below:
Connie 27
95 26
James 32
99 26
Susan 5
67 25
Jake 24
65 20
Phil 29
66 32

Students with grades between 70 and 79:

But should print this:

Connie has an average grade of 85%. You will receive a B in this class.
James has an average grade of 92%. You will receive a A in this class.
Susan has an average grade of 52%. You will receive a F in this class.
Jake has an average grade of 66%. You will receive a D in this class.
Karen has an average grade of 77%. You will receive a C in this class.

Overall Class Average is 74%.

The following program generates 3 random numbers, then averages them.

The average of 12 34 24 is 23

[fred rosenberger]

Was there a question in here somewhere?

mike statham wrote:

  import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.StringTokenizer;

public class GradesAAA {

public static void main(String[] args) throws IOException   
   {   
      
    String firstName = null, gradeString = null, filename;   
   String strLine;   
    // Initializing new Strings for each range   
    String firstRange = "", secondRange = "", thirdRange = "", fourthRange = "";   
   int grade = 0, linesWithGrades = 0;   
   double avg = 0; 
   
   
      
   filename = ("grades.txt");   
   StringTokenizer st;   
   BufferedReader br;   
    try {   
    br = new BufferedReader(new FileReader(filename)); // Required to read the file   
      
    while ((strLine = br.readLine()) != null) {   
        st = new StringTokenizer(strLine, " ");   
        try {   
            while (st.hasMoreTokens()) {   
                firstName = st.nextToken();  
                
                 
                  
                    gradeString = st.nextToken();   
                    grade = Integer.parseInt(gradeString)/3; 
                    
                    
                      
               if (grade > 0 && grade < 69) {   
                  avg += grade;   
                  linesWithGrades++;   
                        firstRange +=  firstName + "\t" + grade + "\n";   
               } else if (grade > 69 && grade < 80) {   
                  avg += grade;   
                  linesWithGrades++;   
                        secondRange +=  firstName + "\t" + grade + "\n";   
               } else if (grade > 79 && grade < 90) {   
                  avg += grade;   
                  linesWithGrades++;   
                        thirdRange +=  firstName + "\t" + grade + "\n";   
               } else if (grade > 89 && grade < 101) {   
                  avg += grade;   
                  linesWithGrades++;   
                        fourthRange +=  firstName + "\t" + grade + "\n";   
               }   
                    // To avoid adding the wrong data to noData, the variables are cleaned   
                    firstName = "";   
                      
                    gradeString = "";   
         }   
        } catch (Exception e) {   
            // Catches null data for noData   
                
         }   
   }   
                } catch (Exception e) {   
                System.out.println("Exception while reading grades file: " + e);   
            }   
            System.out.println("Students with grades 69 and below: ");   
            System.out.println(firstRange);   
            System.out.println("Students with grades between 70 and 79: ");   
            System.out.println(secondRange);   
            System.out.println("Students with grades between 80 and 89: ");   
            System.out.println(thirdRange);   
            System.out.println("Students with grades of 90 and above: ");   
            System.out.println(fourthRange);   
            System.out.println("Persons with no grade or incomplete data: ");   
               
            System.out.println();   
            System.out.println();   
            System.out.print("The grade point average is" + "\t" + Math.ceil(avg / linesWithGrades));   
            System.out.println();   
   }   
}   
 

Whic prints out this:
Students with grades 69 and below:
Connie 27
95 26
James 32
99 26
Susan 5
67 25
Jake 24
65 20
Phil 29
66 32

Students with grades between 70 and 79:

But should print this:

Connie has an average grade of 85%. You will receive a B in this class.
James has an average grade of 92%. You will receive a A in this class.
Susan has an average grade of 52%. You will receive a F in this class.
Jake has an average grade of 66%. You will receive a D in this class.
Karen has an average grade of 77%. You will receive a C in this class.

Overall Class Average is 74%.

The following program generates 3 random numbers, then averages them.

The average of 12 34 24 is 23

[dennis deems]

You have written procedural code using an object-oriented language. Your main method is entirely -- I might say, single-mindedly -- focused on producing Strings to print out. How could you expect to produce the required output this way?

You need to break up your task into smaller bits. What will you do when you are asked for more information about the grades? Say we desire the mode or median scores? You'll have to add more code to the main method. As requirements are added the main method will quickly become impossible to manage.

Use objects. Maybe a Student object that contains a set of scores? Then make a method that can calculate the average of a bunch of scores, given a Student object. Something like that. One simple object can simplify your task a great deal. Don't write procedural code!