title: Binary searching NSArray without having the object to search but a condition
body: <p>So, I have this array of objects with <code>NSNumber</code>s in it. I have a number of my own and I need to find a number in the array that's greater than my number by least margin. </p>
  
  <p>How do I employ binary search for this? </p>
  
  <p>The method : <code>indexOfObject:inSortedRange:options:usingComparator</code> accepts the object as a parameter and I don't have it. How do I do the binary search with this condition but without an object?</p>