练习1
public static void main(String[] args) { Random rm=new Random(); List<Integer> list=new ArrayList<>(); for(int i=0;i<6;i++) { int m = rm.nextInt(33) + 1; list.add(m); } for (int i = 0; i < list.size(); i++) { System.out.println(list.get(i)); } }练习2
public static void main(String[] args) { ArrayList<Student> list=new ArrayList<>(); Student student1=new Student("zhang",21); Student student2=new Student("lisi",22); list.add(student1); list.add(student2); for (int i = 0; i < list.size(); i++) { System.out.println(list.get(i).getName()+" "+list.get(i).getAge()); } }练习3
public static void print(ArrayList list){ for (int i = 0; i < list.size(); i++) { if(i==list.size()-1){ System.out.print(list.get(i)+"}"); }else if(i==0){ System.out.print("{"+list.get(i)+"@"); }else{ System.out.print(list.get(i)+"@"); } } }练习4
public static void main(String[] args) { ArrayList<Integer> list1 = new ArrayList<>(); ArrayList<Integer> list2 = new ArrayList<>(); Random rm = new Random(); for(int i=0;i<20;i++){ int num = rm.nextInt(); list1.add(num); } for (int i = 0; i < list1.size(); i++) { if(list1.get(i)%2==0){ list2.add(list1.get(i)); } } System.out.println(list2); }