import java.util.*;

public class GenericsDemo {
    
    public static void main(String[] args) {
        demoIntegerList();
        demoAutoboxing();
        demoForeach();
    }
    
    public static void demoIntegerList() {
        
        System.out.println("\ncalling demoIntegerList()");
        
        List<Integer> myIntList = new LinkedList<Integer>(); // 1’
        
        myIntList.add(new Integer(123)); //2’
        
        Integer x = myIntList.iterator().next(); // 3’
        
        System.out.println(x);
    }
    
    public static void demoAutoboxing() {
        
        System.out.println("\ncalling demoAutoboxing()");
        
        List<Integer> myIntList = new LinkedList<Integer>(); // 1’
        
        myIntList.add(321); //2’
        
        int x = myIntList.iterator().next(); // 3’
        
        System.out.println(x);
    }

    public static void demoForeach() {
        
        System.out.println("\ncalling demoForeach()");
        
        List<Integer> myIntList = new LinkedList<Integer>(); // 1’
        
        myIntList.add(1); //2’
        myIntList.add(2); //2’
        myIntList.add(3); //2’
        myIntList.add(4); //2’
        
        for (int i: myIntList) {
            System.out.println(i);
        }
    }
}