# I need help with while loop.

• September 20th, 2011, 10:04 PM
unknowncode
I need help with while loop.
Code java:

```import java.util.Scanner;       public class ExamScores { public static void main(String[] args) { Scanner input = new Scanner(System.in);   int gradeA = 0; int gradeB = 0; int gradeC = 0; int gradeD = 0; int gradeF = 0; int scores, totalnumber;   System.out.println("Enter all your exam scores here: "); System.out.println("Enter a negative number after "); System.out.println("you have entered all the scores.");     totalnumber = 0; scores = input.nextInt();   while (scores >= 0) {   scores = input.nextInt(); totalnumber++;   if (scores >= 90 & scores <= 100){ gradeA = gradeA + 1;} else if (scores <= 89 & scores >= 80){ gradeB = gradeB + 1;} else if (scores <= 79 & scores >= 70){ gradeC = gradeC + 1;} else if (scores <= 69 & scores >= 60){ gradeD = gradeD + 1;} else if (scores < 60 & scores >= 0){ gradeF = gradeF + 1;} else System.out.println("");   }   System.out.println ("Total number of grades = " + totalnumber + "\nNumber of A's = " + gradeA + "\nNumber of B's = " + gradeB + "\nNumber of C's = " + gradeC + "\nNumber of D's = " + gradeD + "\nNumber of F's = " + gradeF);   } }```

for example the input:
98 87 78 77 85 68 55 -1

The output:

Total number of grades = 7
Number of A's = 1
Number of B's = 2
Number of C's = 2
Number of D's = 1
Number of F's = 1
• September 21st, 2011, 07:19 AM
KevinWorkman
Re: I need help with while loop.

I've added highlight tags as well as moved your post to a more appropriate forum.
• September 25th, 2011, 06:15 AM
vivjo
Re: I need help with while loop.
Hey,
how wiil the while loop termimates ,

the variable score never changes after inputting from keyboard and moreover to put a series of scores use "Input Statement" within While
Hope this helps
Cheers
• September 25th, 2011, 06:26 AM
vivjo
Re: I need help with while loop.
"Change this"
scores=1;

Before( scores>0)

& is Bitwise And Operator
Use && and it would work
if(a>b && a>c)
The code is working fine
• September 26th, 2011, 07:16 AM
KevinWorkman
Re: I need help with while loop.
Quote:

Originally Posted by vivjo
& is Bitwise And Operator
Use && and it would work
if(a>b && a>c)
The code is working fine

Hmm, that should still work. Using a single & (or |) instead of the double && or || will simply cause both statements to be evaluated instead of shortcutting. With double &&, if the left side is false, it doesn't bother testing the right side. Same with double ||, only with true instead of false.

With a single & or |, it tests both sides no matter what. Try out different values for t with both & and && in this program:

Code java:

```public class Test{ public static void main(String... args) { int x = 9;   boolean test = testVariable(x, 4) & testVariable(x, 5); System.out.println(test); }   public static boolean testVariable(int x, int t){ System.out.println("Testing: " + x + " < " + t + ": " + (x < t) ); return x < t; } }```