Help setting up an array and other issues

[mike statham]

What I need is read from a file which it does but I need it to be a file of any size, not just set as I've got set at 15.

Then I need to print out A=2 B=2 C=2 D=2 F=2 just a sample showing how many each student earn what grade.

I know that im probally making things worse than they should, but when you self teaching your self........

Any help is appreciated!

package average;

import java.io.FileReader;
import java.util.Scanner;

/**
 *
 * @author Big daddy
 */
class Grades {
 static public void main(String[] args) throws Exception {


	     
     //create scanner for the file
		Scanner input = new Scanner(new FileReader("grades.txt"));
		int []numGrade = new int[15];
		String[] name = new String[15]; // stores name of each student
		int[] avgMarks = new int[15]; // stores avg marks of each student
		String[] letterGrade = new String[15]; // stores grade of each student
		int totalMarks = 0;  // stores total marks 
		int avg =0;  
       
		for (int i = 0; i < 15; i++) {
			name[i] = input.next();
			avg = 0;
			for (int j = 0; j<3; j++) {				
				numGrade[j] = input.nextInt();			
				avg += numGrade[j];
				if (j == 2) {
					avgMarks[i] = avg/3;
					totalMarks += avgMarks[i];
				}	
			}
		
		}
		
		// get the grade 
		
		for (int i=0; i<15; i++) {
                    
            if (avgMarks[i] < 60) {
				letterGrade[i] = "F";
            
			}	else if (avgMarks[i] < 70) {
				letterGrade[i] = "D";
            
			}	else if (avgMarks[i] < 80) {
				letterGrade[i] = "C";
            
			}  else if (avgMarks[i] < 90){
				letterGrade[i] = "B";
            
			}  else {
				letterGrade[i] = "A";
                                
                                
                      // initializing int
int inputsProcessed = 0;
int A = 0;
int B = 0;
int C = 0;
int D = 0;
int F = 0;



//process A's
if (avgMarks >= 90){ 
//add each occurence
++A;
}
//process B's
else if (avgMarks >= 80){
//add each occurence 
++B;
}
//process C's
else if (avgMarks >= 70){
//add each occurence 
++C;
} 
//process D's
else if (avgMarks >= 60){
//add each occurence
++D;
}
//process F's
else if (avgMarks >= 0){
//add each occurence
++F;
}
//else {
//System.out.println("Proper input was not input");
System.out.println("Total number of grades:" + inputsProcessed); 
System.out.println("Number of A's = " + A );
System.out.println("Number of B's = " + B );
System.out.println("Number of C's = " + C );
System.out.println("Number of D's = " + D );
System.out.println("Number of F's = " + F );
}          
                                
                                
                                
                                
         }
		}
      
       		
		for (int i = 0; i<15; i++) {
			System.out.printf("%s\t has an average grade of  %d%%.  You will receive a %s in this class. \n", name[i], avgMarks[i], letterGrade[i]);
         		
		System.out.printf("\nOverall Class Average is %d%%.\n",totalMarks/15);
      
                
                
                
                
                
                
                
                
                
       }    
      
      //generates three random numbers between 0 and 50, calculates the average.
      int one,two,three;
      one=(int)(Math.random()*(51));
      two=(int)(Math.random()*(51));
      three=(int)(Math.random()*(51));

      int average=(one+two+three)/3;
      System.out.println("\n\nThe following program generates 3 random numbers, then averages them.");
      System.out.println("\nThe average of\t"+one+"  "+two+"  "+three+"  is   "+average);


   }
   }
  




 

[Zeeshan Sheikh]

Try ArrayList as it grows dynamically.