java的list详解_javalist讲解

1 List 的常用方法：

public class TestList {
    /**
     * 测试add/remove/size/isEmpty/contains/clear/toArrays等方法
     */
    public static void test01() {
        List<String> list = new ArrayList<String>();
        System.out.println(list.isEmpty()); // true,容器里面没有元素
        list.add("高淇");
        System.out.println(list.isEmpty()); // false,容器里面有元素
        list.add("小七");
        list.add("小八");
        System.out.println(list);
        System.out.println("list的大小：" + list.size());
        System.out.println("是否包含指定元素：" + list.contains("小七"));
        list.remove("小九");
        System.out.println(list); 
        Object[] objs = list.toArray();
        System.out.println("转化成Object数组：" + Arrays.toString(objs));
        list.clear();
        System.out.println("清空所有元素：" + list);
    }
    public static void main(String[] args) {
        test01();
    }
}

2 自己模拟ArrayList

package com.bjsxt.list;
  
public class SxtArrayList {
    private Object[] elementData;//核心数组
    private int size;
 
    public int size() {
    return size;
    }
 
    public boolean isEmpty() {
    return size == 0;
    }
 
    public SxtArrayList() {
    this(10);//调用本类的构造器传入10
    }
 
    public SxtArrayList(int initialCapacity) {
    if (initialCap