Java – reverse loop for array countdown

I received an error

Exception in thread "main" java.lang.Arrayindexoutofboundsexception: 10
    at Reverse.main(Reverse.java:20).

The syntax is correct, so I'm not sure why there are errors when compiling?

public class Reverse {

public static void main(String [] args){
    int i,j;


    System.out.print("Countdown\n");

    int[] numIndex = new int[10]; // array with 10 elements.

    for (i = 0; i<11 ; i++) {
        numIndex[i] = i;// element i = number of iterations (index 0=0,1=1,ect.)
    }

    for (j=10; j>=0; j--){ // Could have used i,doesn't matter.
        System.out.println(numIndex[j]);//indexes should print in reverse order from here but it throws an exception?
    }
}

}

Solution

Java uses 0 - based array indexes When you create an array of int new [10] with a size of 10, it will create 10 integer 'units' in the array The index is: 0,1,2, 8,9.

Your cycle counts to an index that is less than 11 or 10 and does not exist