update in list in java without knowing index code example

Example: how to update a list index value in java

public class ArrayListExample 
{
    public static void main(String[] args) 
    {
        ArrayList<String> list = new ArrayList<>();
         
        list.add("A");
        list.add("B");
        list.add("C");
        list.add("D");
         
        System.out.println(list);
 
         
        //Replace C with C_NEW
 
 
        //1 - In multiple steps
         
        int index = list.indexOf("C");
         
        list.set(index, "C_NEW");
         
        System.out.println(list);
 
 
        //2 - In single step replace D with D_NEW
 
        list.set( list.indexOf("D") , "D_NEW");
 
        System.out.println(list);
    }
}