I don’t understand how lastIndexOf method works in java

Posted on by mtoplistChuyên mục:Top List

I have to write a method called LastIndexOf that accepts an integer value as a parameter and that returns the index in the list of the last occurrence of the value, or -1 if the value is not found. This is the code I have but it doesn’t return anything. To me it looks that it always is going to return -1 but I can’t see it on the output because it doesn’t print what the method returns.

these are the values that list stores.

list -> [2, 5, 7, 24, 5, 9, 13, 2]

    public class LastIndexOf {

    public static void main(String[] args) {

    System.out.println("index of 5 = " + list.lastIndexOf(5)); // should to return index of 5= 4
    System.out.println("index of 100 = " + list.lastIndexOf(100)); // should return index of 100 = -1

    }

    public static int lastIndexOf (int element) {
    int index = 0;
    ListNode current = list;
    while (current != null) {
       if (current.data == element) {
           return index;
       }
       index ++;
       current = current.next;
    }
    return -1;
    }
}

This is the output I get:

index of 5 = 
index of 100 =

mtoplist