ArrayList的使用

public class ArrayListDemo {
  public static void main(String[] args) {
    // 创建集合对象
    ArrayList array = new ArrayList();

    // 创建元素对象，并添加元素
    array.add("hello");
    array.add("world");
    array.add("java");

    // 遍历
    Iterator it = array.iterator();
    while (it.hasNext()) {
      String s = (String) it.next();
      System.out.println(s);
    }

    System.out.println("-----------");

    for (int x = 0; x < array.size(); x++) {
      String s = (String) array.get(x);
      System.out.println(s);
    }
  }
}

import java.util.ArrayList;
import java.util.Iterator;
class Student {
  private String name;
  private int age;

  public Student() {
    super();
  }

  public Student(String name, int age) {
    super();
    this.name = name;
    this.age = age;
  }

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public int getAge() {
    return age;
  }

  public void setAge(int age) {
    this.age = age;
  }

}
public class ArrayListDemo2 {
  public static void main(String[] args) {
    // 创建集合对象
    ArrayList array = new ArrayList();

    // 创建学生对象
    Student s1 = new Student("武松", 30);
    Student s2 = new Student("鲁智深", 40);
    Student s3 = new Student("林冲", 36);
    Student s4 = new Student("杨志", 38);

    // 添加元素
    array.add(s1);
    array.add(s2);
    array.add(s3);
    array.add(s4);

    // 遍历
    Iterator it = array.iterator();
    while (it.hasNext()) {
      Student s = (Student) it.next();
      System.out.println(s.getName() + "---" + s.getAge());
    }

    System.out.println("----------------");

    for (int x = 0; x < array.size(); x++) {
      // ClassCastException 注意，千万要搞清楚类型
      // String s = (String) array.get(x);
      // System.out.println(s);

      Student s = (Student) array.get(x);
      System.out.println(s.getName() + "---" + s.getAge());
    }
  }
}