Java BinarySearch

Question

Can I get some help please? I have tried many methods to get this to work i got the array sorted and to print but after that my binary search function doesnt want to run and

Answer 1

/**
HOPE YOU LIKE IT
A.K.A Binary Search
Take number array of 10 elements, input a number a check whether the number 
is present:
**/
package array;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.IOException;
class BinaryS
{
    public static void main(String args[]) throws IOException
    {       
    BufferedReader br=new BufferedReader(new InputStreamReader(System.in));      
    System.out.print("Enter a number: ");
    int n=Integer.parseInt(br.readLine());
    int a[]={10,20,30,40,50,60,70,80,90,100};
    int upper=a.length-1,lower=0,mid;
    boolean found=false;
    int pos=0;
    while(lower<=upper)
    {
        mid=(upper+lower)/2;
        if(na[mid])lower=mid+1;
        else
        {
            found=true;
            pos=mid;
            break;
        }
    }
    if(found)System.out.println(n+" found at index "+pos);
    else System.out.println(n+" not found in array");
}
}