java - While loop doesnt end in iterative binary search -

i'm writing binary search uses iteration instead of recursion , not returning anything. i've debugged down while loop not ending can't seem figure out went wrong.

here code:

public static <e extends comparable> boolean binarysearchiterative(e[] array, e obj) {     int first = 0;     int last = array.length - 1;     while(first <= last) {         int middle = (first + last) / 2;         if(array[middle].equals(obj)) return true;         else if(obj.compareto(array[middle]) < 0) first = middle - 1;         else first = middle + 1;     }     return false; } 

and yes, list ordered ;)

in second else if part need set last instead of first -

else if(obj.compareto(array[middle]) < 0) last = middle - 1;