一、从动态数组到二维 ArrayList：核心概念 ArrayList 是数组（Array）的动态版本。原生数组在声明时必须预定义长度，而 ArrayList 内部维护一个可扩容的底层数组，当元素数量超过当前容量时会自动增长，因此使用者在多数场景下无需关心容量上限。

原创 最新推荐文章于 2026-09-17 09:51:31 发布 · 220 阅读 ArrayList作为Java集合框架中最常用的动态数组实现，其底层通过数组存储 ...

This repo has various data structures and algorithms implementations and problems around that for preparing the coding interviews. 🚀 👨‍💻💻 🚩 ...

ArrayList is a dynamic array. In other words, you don't need to specify the size at the beginning, you can store values one after another as you go.

main Ex11-Convert HashSet to ArrayList .md Ex12-Add Elements from an Array into a TreeSet.md Ex13-Elements of an Array.md Ex14-First Unique Number in a Stream.md Ex15-Value Existence Check in a ...

In Java, when defining lists or maps, there is a syntax style that uses two sets of curly braces, {{ ... }}, known as Double Brace Initialization. First, take a look at this writing style, which makes ...