Collection-List

public class DemoArrayList {
    public static void main(String[] args) {
        List<Object> list = new ArrayList<>();
        list.add("mysql");
        list.add("mysql");
        list.add("java");
        list.add("java");
        
        //add
        list.add(2,"Java");
        list.forEach(System.out::println);//foreach
        System.out.println("------------------");
        
        //get
        System.out.println(list.get(2));
        Iterator<Object> iterator = list.iterator();//迭代器
        while (iterator.hasNext()){
            System.out.println(iterator.next());
        }
        System.out.println("------------------");
        
        //remove
        System.out.println(list.remove(2));
        for (Object o : list) {//Lambda
            System.out.println(o);
        }
        System.out.println("------------------");
        
        //set
        list.set(1, "Mybatis");
        for (int i = 0; i < list.size(); i++) {//for循环
            Object o = list.get(i);
            System.out.println(o);
        }
    
    }
}

public class DemoLinkedList {
    public static void main(String[] args) {
        //做个队列：先进先出
        LinkedList<String> queue = new LinkedList<>();
        queue.addLast("1号");//入队
        queue.addLast("2号");
        queue.addLast("3号");
        queue.addLast("4号");
        System.out.println(queue);//[1号, 2号, 3号, 4号]
        
        System.out.println(queue.removeFirst());//出队
        System.out.println(queue.removeFirst());
        System.out.println(queue);//[3号, 4号]
    
        //做个栈,先进后出
        LinkedList<String> stack = new LinkedList<>();
        stack.push("1号");//压栈,this.addFirst()
        stack.push("2号");
        stack.push("3号");
        stack.push("4号");
        System.out.println(stack);//[4号, 3号, 2号, 1号]
    
        System.out.println(stack.pop());//弹栈，this.removeFirst()
        System.out.println(stack.pop());//3号
        System.out.println(stack);//[2号, 1号]
    }
}