1. PHP7 数据结构与算法之前言

Data structures and algorithms are an integral part of software application
development.

数据结构与算法在软件程序开发中一个完整的章节。

Whether we are building a web-based application, a CMS, or a standalone backend system using PHP, we need to apply algorithms and data structures all the time.

不论我们使用 PHP 构建基于 WEB 的程序，比如CMS,或者一个独立的后台程序，我无时不刻需要应用数据结构与算法。

Sometimes, we do that without noticing and sometimes without giving proper attention to it.

一些时候，我们没有意识到它已经完成了，因而也没有给予足够的重视。

Most developers think that these two
topics are really difficult and there is no point in paying attention to details as PHP has lots of built-in support for data structures and algorithms.

大多数开发人员都认为这两个主题是非常困难的，在 PHP 中内置了大量对数据结构和算法的支持，所以并不需要过于关注细节。

In this book,we will focus on the basics and practical examples of PHP data structures and algorithms so that we know what data structures are, why to choose them, and where to apply which algorithms.

在这本书中，我们将将焦点集中于那些基本而且实用的数据结构和算法，他们使用 PHP 描述，并且我们将直到什么是数据结构，为什么选用他们，并且如何应用那些算法。

This book is designed for novice as well as experienced PHP programmers.

这本书是为新手或者有经验的PHP程序员设计的。

The book starts from basic topics and moves on to more advanced topics.

这本书的主题将由浅入深。

We have tried to accommodate lots of examples with images and explanations in this book so that you can understand the concepts properly in visual form and with practical examples.

我们在这本书中包含了大量的图片和说明，使得您能通过可视化的形式以及大量的实例来理解这些概念。