本内容遵循CC 4.0 BY-SA版权协议 本文聚焦 Java 集合框架中的 ArrayList，从它的定义与核心特性出发，系统梳理所有常用接口的作用与返回值，最后给出整体总结。适合作为学习笔记或面试速查。 在集合框架中，ArrayList 是一个普通的类，实现了 List 接口，它的本质是 ...

1.2 ArrayList的底层存储，决定了删除成本不是零 ArrayList底层就是一个 Object [] 数组，按索引访问是O (1)，这大家都熟。但删除操作不是把某个格子清空就完事，它要做数组搬移： remove (int index) 会把 index 之后的所有元素依次前移一位，再把最后一个格子置 null ，最后修改 size 。

ParkEngine is a console-based parking lot management system developed in Java. It models the complete parking lifecycle, including vehicle entry, parking spot allocation, ticket generation, vehicle ...

A Java-based ATM Management System designed to simulate essential banking operations such as customer authentication, balance inquiry, deposits, withdrawals, fund transfers, account registration, and ...