Question

I wrote the following code for finding the last zero index in an array:

public class Stack {
    public static void main(String[] args){
        int[] a=new int[5];
        a[0]=1;
        a[1]=0;
        a[2]=90;
        a[3]=0;
        a[4]=4;
        findLast(a);
    }
    public static int findLast(int[] x){
        for(int i=0;i<x.length;i++){
         if(x[i]==0){
             System.out.println(i);             
         }
        }
        return 0;
    }
}

The output is as follows:

1
3

What I really want is the index 3.

Answer 1

• Start at the end of the array (i.e. i=x.length-1)
• Decrement i rather than incrementing (i.e. use i--)
• Stop as soon as you reach zero (i.e. add break after println).
• Make your stopping condition such that the loop processes element at index zero.