Collections.binarySearch() in Java

Question

I\'m using the binarySearch() method to find the position of an element in the list. And I don\'t understand why the index is -6. I see that the element is at the position 1

Answer 1

Apart from the need for the list being sorted, binary Search

returns the index of the search key, if it is contained in the list; otherwise, (-(insertion point) - 1)

(Javadoc)

Ie: a negative index designates the negative of the index at which the item being searched would be placed if it were present, minus 1.

I.e.

-1 means it would be placed at index 0

-6 means it would be placed at index 5.