function found = binarySearch(target, data)
    found = 0; % target in data? we don't know yet
    
    % Nothing to find in an empty array:
    if isempty(data)
        return
    end
    
    % Now need to search array:
    % two ways to consider: [low, high] or [left, right]
    %                       where low <= high, left <= right
    
    low = 1;  % first index (left)
    high = length(data); % last index (right)
    
    % While array indicies haven't crossed, keep searching:
	while low <= high
	    mid = floor((low + high)/2);
        % if target is in middle of array, we've succeeded:
        if target==data(mid)
		    found = mid;
            return;
        elseif target > data(mid) % L < M < T < H
            low = mid+1;  % update left index (increase by 1 because M < T)
        elseif target < data(mid) % L < T < M < H
    		high = mid-1; % update right index (decrease by 1 because M > T)
	    else
		    error('something terrible happened');
        end

    end

   % found was set to zero, so if we reach down here,
   % item was not found