程序代码：

import java.util.Iterator;
import java.util.List;

public class Test {
    public static void main(String[] args) {
        List<String> list = null;
        try {
            for (String string : list) {
                System.out.println(string);
            } 
        } catch (Exception e) {
            e.printStackTrace();
            System.err.println(e.getMessage());
        }
        try {
            for (Iterator iterator = list.iterator(); iterator.hasNext();) {
                String string = (String) iterator.next();
                System.out.println(string);
            } 
        } catch (Exception e) {
            e.printStackTrace();
            System.err.println(e.getMessage());
        }
        System.out.println("关于foreach报空指针的代码解释!");
        
    }
}