how to write java program that read 5 numbers and calculate how many numbers has value from 0-9

Question

import java.util.Scanner;
public class good
{
  public static void main(String[] args) {
    Scanner variable = new Scanner(System.in);

    int i = 0, counter = 0, n = 0;

    for (i = 0; i < 5; i++) {
        n = variable.nextInt();
    }
    if ((0 <= n) && (n <= 9)) {
        counter++;
    }
    System.out.println("the number of values enterd from 0-9 is    " + counter);
   }

}

I have no errors in my program but I'm not getting a right answer. For example :

 ----jGRASP exec: java good

5
6
4
the number of values enterd from 0-9 is    0

 ----jGRASP: operation complete.

I shoud get "3" but I get "0"

Answer 1

Your code doesn't work because you are missing brackets on your for loop. You just execute n=variable.nextInt() five times without checking it, and then check it. If you include brackets this should work.

Answer 2

You need to use braces around your the inner for loop

import java.util.Scanner;
    public class good
    {
       public static void main(String[] args)
       {

    Scanner variable=new Scanner(System.in);

    int i=0,counter=0,n=0;

    for(i=0;i<5;i++){
       n=variable.nextInt();
       if((0<=n)&&(n<=9))
       counter++;
    }
    System.out.println("the number of values enterd from 0-9 is    "+counter);

    }
 }

Answer 3

Your main problem is not understanding when your for loop ends. You should add brackets { } around loops and if statements, so that only the code inside those brackets executes when the conditions are met.

public static void main(String[] args)
{
    Scanner variable = new Scanner(System.in);

    int counter = 0;

    for(int i = 0; i < 5; i++)
    {   
        int n = variable.nextInt();

        if(0 <= n && n <= 9)
        {
            counter++;
        }
    }
    variable.close();

    System.out.println("the number of values enterd from 0-9 is: " + counter);
}

You should also close your Scanner .

Short tutorial on loops .