Chapter 11 Exercise 4, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

11.4 (Maximum element in ArrayList) Write the following method that returns the maximum value in an ArrayList of integers. The method returns null if the
list is null or the list size is 0.
public static Integer max(ArrayList<Integer> list)
446 Chapter 11 Inheritance and Polymorphism
Write a test program that prompts the user to enter a sequence of numbers ending
with 0, and invokes this method to return the largest number in the input.

import java.util.ArrayList;
import java.util.Scanner;
 

public class Exercise_04 {

    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);
        ArrayList<Integer> list = new ArrayList<>();
        System.out.print("Enter input end with zero to stop: ");
        int temp;
        do {
            temp = input.nextInt();
            if (temp != 0) {
                list.add(temp);
            }
        } while (temp != 0);

        System.out.println("Max number is " + max(list));
    }

    public static Integer max(ArrayList<Integer> list) {

        if (list == null || list.isEmpty()) return null;

        int max = list.get(0);
        for (int i : list) {
            if (i > max) {
                max = i;
            }
        }

        return max;

}


}