title: binarySearch function error
body: <pre><code>import java.lang.*;
  import java.util.*;
  public class AnotherArrayPractice{
  public static void main (String[] args){
    int [] arr={130,10};
    System.out.println(arr[1]);
    System.out.println(Arrays.binarySearch(arr,10));
    System.out.println(Arrays.binarySearch(arr,130));
  
    }
  }
  </code></pre>
  
  <p>The print result is as follow: 10, -1, 0. 
  I am confused as to why the <code>binarySearch(arr,10)</code> gives me <code>-1</code> while in fact <code>10</code> is inside the array</p>