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beginners
1748 posts
状态模式深度指南：构建可动态切换行为的艺术
状态模式深度指南：构建可动态切换行为的艺术 概述 状态模式（State Pattern）是一种行为型设计模式，它允许对象在内部状态改变时改变其行为。看起来对象似乎修改了其类。这种模式是解决复杂状态转换逻辑的利器，特别适合用于工作流引擎、游戏开发、订单处理系统等场景。 核心概念 状态模式的核心思想是：将每个状态封装为独立的类，对象的行为取决于其当前状态，而状态之间的转换由状态类自己管理。 关键角色 Context（上下文）：维护当前状态的实例，负责将请求委托给状态对象处理 State（抽象状态）：定义所有具体状态的共同接口 ConcreteState（具体状态）：实现各个具体状态的行为，并负责状态转换 为什么需要状态模式？ 传统方式的困境 想象一个订单系统，订单有多种状态：待支付、待发货、已发货、已完成、已取消。每个状态下可以执行不同的操作。 // 传统的if-else方式 class Order {…
Vector Databases: Search by Meaning, at Scale
Embeddings turn meaning into vectors (last post). But if you have a million of them, how do you…
printf() and scanf() in C: Understanding Input and Output
One of the first things every C programmer learns is how to interact with users. A program that…
Optimizing Django ORM Queries: A Practical Guide to select_related and prefetch_related
1. Introduction Django’s ORM is one of its greatest strengths. It abstracts away raw SQL, lets you express…
How I Chose My Web Development Path as a Beginner
Choosing a learning path is one of the most critical decisions you make as a beginner. When I…
UseState in React (A beginner’s guide)
Your password bar goes from “weak” to “strong” when you add characters. Have you ever wondered how React…
Python for Beginners — Part 1: Getting Started & Syntax
A beginner-friendly series on learning Python from scratch, one concept at a time. If you’ve ever wanted to…
If you’re a software developer just starting out and you’ve ever wondered how senior devs think while they build, this is for you.
A junior dev asked me something recently that actually made me think. He said: “As a software developer…
What Is a Zone File? Understanding DNS Zone Structure
Every domain’s DNS records have to live somewhere. That somewhere is a zone file: a text-based blueprint that…
The First Message Sent Over the Internet Was ‘LO’
The first message ever sent across the network that became the internet was not “Hello, world.” It was…
