I was trying out a java code to insert a new element into an array, I understand most of the program except for a line of code: "int newindex = -index-1;". Why does a negative sign used in front of the index?

Here is the full program:

```
public class ArrayManipulation2 {

    public static void main(String[] args) {

        int[] array = {6,3,5,2,-9,-5,-1,0};
        Arrays.sort(array);
        printArray(array);

        int index= Arrays.binarySearch(array, 1);
        int newindex = -index-1;

        array = insertElement(array, 1, newindex);
        printArray(array);
    }

    public static void printArray(int[] array){

        for(int i=0; i<array.length; i++){
            if(i!=0){
                System.out.print(", ");
            }
            System.out.print(array[i]);
        }
        System.out.println();

    }

    public static int[] insertElement(int[] orginal, int element, int index){
        int length = orginal.length;
        int[] destination = new int[length+1];
        System.arraycopy(orginal, 0, destination, 0, index);
        destination[index]=element;
        System.arraycopy(orginal, index, destination, index+1, length-index);

        return destination;

    }
} 

```

I need to know why the new index is specified as "-index-1"?.