Question

public static void main(String args[])
{
    double arr[] = {1,-6.3,9000,67.009,1.1,0.0,-456,6,23,-451.88};

    ArrayList<Integer> List = new ArrayList<Integer>();

     List.add(1);
     List.add((int) -6.3);
     List.add(9000);
     List.add((int) 67.009);
     List.add((int)1.1);
     List.add((int)0.0);
     List.add(-456);
     List.add(6);
     List.add(23);
     List.add((int)451.88);
}

public static int ArrayListMax(ArrayList List)
{

    for (int i=0; i<List.size(); ++i)
    {
        System.out.println(List.get(i));
    }

The error is in:

  public static int ArrayListMax(ArrayList List) 

This is probably a very nooby mistake, but I’m new to Java so forgive me.

Any help please?

Thank you.

EDIT:

I want the ArrayListMax method to print the size of the List!

Answer 1

Assuming you are trying to get the maximum value in your List in the method arrayListMax, you need to return an integer in accordance with your method signature, which the error is telling you

This method must return a result of type int

Instead of printing all the values in the list, you could do:

public static int arrayListMax(List<Integer> List) {
   return Collections.max(list);
}

---

Use Java Naming Conventions. Method & variable names begin with a lowercase letter. Using this approach helps avoid confusion between instances & types (e.g. in the case of List in the main method).