help w/ storing/scanning numbers in arrays

• November 17th, 2010, 01:10 PM
robertsbd
help w/ storing/scanning numbers in arrays
these are my instructions
A Computer Technology Instructor has a small class of 10 students. The instructor evaluates the performance of students in the class by administering 2 midterm tests and a Final Exam.

Write a program that prompts the instructor to enter the 10 grades of Midterm 1 and store these numbers in an array. Next prompt for the 10 grades of Midterm2 and store these numbers in a different array. Next prompt for the 10 grades of the Final Exam and store these in a different array. Next add Midterm1 to Midterm2 to Final and store the total of grades in a different array. Next, scan the array that has the totals and identify the minimum grade and maximum grade. Inform the instructor of the minimum grade and maximum grade.

Note : do not assume that the grades are in the range 0 to 100. Your program should function properly whether the grades are in the range 0 to 100 or any other range.
*I'm using eclipse btw

it prompts me to enter my numbers and stores them in the array correctly but when it tells me what my lowest score it says 0.0 and my highest score is 0.0...also, im not sure exactly how to add the total of midterm1 to midterm2 to final exam or how scan the array..and it repeats my highest and lowest score

so far this is my output after i enter the grades

You have entered following grades for midTerm2: [2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0]
You have entered following grades for Final Exam: [2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 2.0]

here is my code

Code java:

```import java.util.Scanner; import java.util.Arrays;   public class Assign9_Roberts   { public static void main(String[] args) { //input scanner Scanner input = new Scanner(System.in);   //Prompt User for midterm1 grades double[]midTerm1= new double [10]; for (int A = 0; A <midTerm1.length; A++){ System.out.println("Please enter MidTerm1 grade:"); midTerm1[A] = input.nextInt(); } System.out.println("Now");   //Prompt User for midterm2 grades double[]midTerm2=new double[10]; for(int B=0; B<midTerm2.length;B++){ System.out.println("Please enter a MidTerm2 grade:"); midTerm2[B] = input.nextInt(); } System.out.println("Now");   //Prompt User for Final Exam grades double[]finalExam = new double[10]; for(int C = 0; C<finalExam.length; C++){ System.out.println("Please enter a Final Exam grade:"); finalExam[C] = input.nextInt(); } int [] grades = new int [10]; int max = 0;   //Display highest score for (int t = 0; t < grades.length; t ++) { if (grades[t] > max) { max = grades[t]; }   System.out.print("Your highest test score is: " + max);   //Display lowest score int min = 0; if(grades[t] < min) { min = grades[t]; } System.out.print("Your lowest test score is: " + min); }   System.out.print("You have entered following grades for midTerm1: "); System.out.println(Arrays.toString(midTerm1)); System.out.print("You have entered following grades for midTerm2: "); System.out.println(Arrays.toString(midTerm2)); System.out.print("You have entered following grades for Final Exam: "); System.out.println(Arrays.toString(finalExam));   }   }```

also this is cross posted...thanks guys
help w/ storing/scanning numbers in arrays - Java Forums
• November 17th, 2010, 01:29 PM
javapenguin
Re: help w/ storing/scanning numbers in arrays
/Display highest score

Code java:

``` for (int t = 0; t < grades.length; t ++) { if (grades[t] > max) { max = grades[t]; }```

Well, since you put nothing in your grades array, all the values are null.
• November 17th, 2010, 07:48 PM
robertsbd
Re: help w/ storing/scanning numbers in arrays
ok here is my updated code...when i run it, it prompts me to enter a grade and when i do i receive this error:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 10
at Assign9_Roberts.main(Assign9_Roberts.java:29)

Code java:

```import java.util.Scanner; import java.util.Arrays;   public class Assign9_Roberts   { public static void main(String[] args) { //input scanner Scanner input = new Scanner(System.in);   double[] grades = new double[10]; double[] midTerm1 = new double[10]; double[] midTerm2 = new double[10]; double[] finalExam = new double[10];     // add midterm1 , midterm2 and final grades and store them in grade array for (int i=0; i<finalExam.length; i++ ) { grades[i] = midTerm1[i] + midTerm2[i] + finalExam[i]; } System.out.println("Please enter a MidTerm1 grade:"); midTerm1[10] = input.nextDouble();     System.out.println("Now");   for(int B=0; B<midTerm2.length;B++){ } System.out.println("Please enter a MidTerm2 grade:"); midTerm2[10] = input.nextDouble();   System.out.println("Now");   for(int C = 0; C<finalExam.length; C++){ } System.out.println("Please enter a Final Exam grade:"); finalExam[10] = input.nextDouble();   double max = grades[0]; double min = grades[0];   //Display highest score for (int t = 0; t < grades.length; t ++) { if (grades[t] > max) { max = grades[t]; }   System.out.print("Your highest test score is: " + max);   //Display lowest score if(grades[t] < min) { min = grades[t]; } System.out.print("Your lowest test score is: " + min); }   System.out.print("You have entered following grades for midTerm1: "); System.out.println(Arrays.toString(midTerm1)); System.out.print("You have entered following grades for midTerm2: "); System.out.println(Arrays.toString(midTerm2)); System.out.print("You have entered following grades for Final Exam: "); System.out.println(Arrays.toString(finalExam));   }   }```
• November 17th, 2010, 08:45 PM
copeg
Re: help w/ storing/scanning numbers in arrays
Arrays are indexed at zero, so if you create an array of size n, the maximum array position you can access is n-1. So in your code, yourarray[10] will be out of bounds, yourarray[9] will be the last index in the array
• November 17th, 2010, 08:59 PM
robertsbd
Re: help w/ storing/scanning numbers in arrays
ok i changed that..thanks, but im still getting the same error..here's my updated code

Code java:

```  import java.util.Scanner; import java.util.Arrays;   public class Assign9_Roberts   { public static void main(String[] args) { //input scanner Scanner input = new Scanner(System.in);   double[] grades = new double[9]; double[] midTerm1 = new double[9]; double[] midTerm2 = new double[9]; double[] finalExam = new double[9];     // add midterm1 , midterm2 and final grades and store them in grade array for (int i=0; i<finalExam.length; i++ ) { grades[i] = midTerm1[i] + midTerm2[i] + finalExam[i]; } System.out.println("Please enter a MidTerm1 grade:"); midTerm1[9] = input.nextDouble();     System.out.println("Now");   for(int B=0; B<midTerm2.length;B++){ } System.out.println("Please enter a MidTerm2 grade:"); midTerm2[9] = input.nextDouble();   System.out.println("Now");   for(int C = 0; C<finalExam.length; C++){ } System.out.println("Please enter a Final Exam grade:"); finalExam[9] = input.nextDouble();   double max = grades[0]; double min = grades[0];   //Display highest score for (int t = 0; t < grades.length; t ++) { if (grades[t] > max) { max = grades[t]; }   System.out.print("Your highest test score is: " + max);   //Display lowest score if(grades[t] < min) { min = grades[t]; } System.out.print("Your lowest test score is: " + min); }   System.out.print("You have entered following grades for midTerm1: "); System.out.println(Arrays.toString(midTerm1)); System.out.print("You have entered following grades for midTerm2: "); System.out.println(Arrays.toString(midTerm2)); System.out.print("You have entered following grades for Final Exam: "); System.out.println(Arrays.toString(finalExam));   }   }```
• November 17th, 2010, 09:31 PM
copeg
Re: help w/ storing/scanning numbers in arrays
You also reduced the size of the array. Remember, the array indexes start at zero, so the last index is n-1 where n is the size of the array. So setting the size to 9, array[9] will be out of bounds and array[8] the last index. Setting to 10, array[10] will be out of bounds but array[9] the last index.
• November 17th, 2010, 09:55 PM
robertsbd
Re: help w/ storing/scanning numbers in arrays
also, trying to submit this assignment within and hour so a quick response is greatly appreciated..thanks

i updated my code and while im not getting the same error its only allowing me to enter 3 numbers and giving me this out put.

100
Now
```  import java.util.Scanner; import java.util.Arrays;   public class Assign9_Roberts   { public static void main(String[] args) { //input scanner Scanner input = new Scanner(System.in);   double[] grades = new double[9]; double[] midTerm1 = new double[9]; double[] midTerm2 = new double[9]; double[] finalExam = new double[9];     // add midterm1 , midterm2 and final grades and store them in grade array for (int i=0; i<finalExam.length; i++ ) { grades[i] = midTerm1[i] + midTerm2[i] + finalExam[i]; } System.out.println("Please enter a MidTerm1 grade:"); midTerm1[8] = input.nextDouble();     System.out.println("Now");   for(int B=0; B<midTerm2.length;B++){ } System.out.println("Please enter a MidTerm2 grade:"); midTerm2[8] = input.nextDouble();   System.out.println("Now");   for(int C = 0; C<finalExam.length; C++){ } System.out.println("Please enter a Final Exam grade:"); finalExam[8] = input.nextDouble();   double max = grades[0]; double min = grades[0];   //Display highest score for (int t = 0; t < grades.length; t ++) { if (grades[t] > max) { max = grades[t]; }   System.out.print("Your highest test score is: " + max);   //Display lowest score if(grades[t] < min) { min = grades[t]; } System.out.print("Your lowest test score is: " + min); }   System.out.print("You have entered following grades for midTerm1: "); System.out.println(Arrays.toString(midTerm1)); System.out.print("You have entered following grades for midTerm2: "); System.out.println(Arrays.toString(midTerm2)); System.out.print("You have entered following grades for Final Exam: "); System.out.println(Arrays.toString(finalExam));   }   }```