After $try is modified, the next instruction is next which goes to the top of the while loop where $try is assigned a new value.    At no point is the value modified by ++$try or --$try used anywhere so you could just do: 

    while ( $lo <= $hi ) {
        my $try = int( ( $lo + $hi ) / 2 );
        if ( $array[ $try ] lt $word ) {
            $lo = $try + 1; # without increment there will be
                            # a dead loop in the 4th case,
                            # see the note at the bottem
        }
        elsif ( $array[ $try ] gt $word ) {
            $hi = $try - 1;
        }
        else {
            return $try
        }
    }

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In reply to Re^5: Binary search algorithm. by jwkrahn
in thread Binary search algorithm. by kindlychung

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