JavaScript是一种直译式脚本语言，它的一个很大的优势就是绝大多数浏览器都包含了JavaScript的解释器，这样我们在学习JavaScript时不需要安装任何开发软件，只要写一个网页文件，嵌入JavaScript代码就能在浏览器中进行代码的调试，很好方便。对于硬件爱好者来说，学习JavaScript还有一个好处就是能让自己的硬件作品更贴近IoT（物联网）应用。了解了JavaScript，我们能够在显示的页面上实现更多的效果，同时，目前有很多硬件也支持用JavaScript来编程。
本书以制作靠前象棋、五子棋、弹球、贪吃蛇、拼图、打飞机等经典游戏为例，带你从零起步，学习JavaScript的编程方法，适合对游戏和编程感兴趣的初学者阅读。而且本书融入了创客的项目式思路，在一个个实例的制作过程中学习知识，语言通俗易懂，图文并茂，会带给你与以往内容枯燥的编程教程接近不同的全新体验。

程晨
创客布道师、创客教育践行者，拥有十多年嵌入式开发经验，技术方面涉猎广泛，先后主持参与十多项军民科研产品的研发，拥有多项发明专利。少年创学院联合创始人兼院长、泺喜教育联合创始人兼技术总监，兼任Intel软件创新大使、中国电子学会全国青少年机器人技术等级考试标准工作组副组长、中国教育技术协会数字教育资源专业委员会专家的职务。本Arduino中文书作者，编著、翻译开源硬件、3D打印、机器人、智能硬件、物联网等领域相关图书十多本，长期在《无线电》杂志刊登技术类文章。参与录制《原来如此》节目，录制多套开源硬件项目视频教程。曾任北京航空航天大学、北京邮电大学特聘讲师，参与清华大学、北京科技大学等多所高校的创新性课程设计。

01   认识JavaScript.................................................................................1
1.1  缘起...............................................................................................................1
1.2  历史...............................................................................................................1
1.3  特性...............................................................................................................2
02  类型和变量.........................................................................................4
2.1  浏览器中的控制台..........................................................................................4
2.2  数字和运算符.................................................................................................5
2.3  变量...............................................................................................................6
2.4  变量命名规则.................................................................................................7
2.5  字符串..........................................................................................................  8
2.5.1  连接字符串… …………………………………………………………………………  9
2.5.2  获取字符串的长度… ………………………………………………………………  10
2.5.3  获取单个字符… ……………………………………………………………………  10
2.5.4  截取字符串… ………………………………………………………………………  11
2.5.5  大小写转化… ………………………………………………………………………  11
2.6  逻辑运算.....................................................................................................  12
2.6.1  布尔类型… …………………………………………………………………………  12
2.6.2  逻辑运算符… ………………………………………………………………………  12
2.6.3  关系运算符… ………………………………………………………………………  14
2.7  underfined 和null......................................................................................  16
2.8  原始类型.....................................................................................................  16
2.8.1  鉴别原始类型… ……………………………………………………………………  16
2.8.2  原始方法… …………………………………………………………………………  17
03  数组................................................................................................18
3.1  创建数组.....................................................................................................  18
3.2  访问数组元素..............................................................................................  18
3.3  修改数组元素..............................................................................................  19
3.4  应用数组.....................................................................................................  20
3.4.1  查看数组长度… ……………………………………………………………………  20
3.4.2  添加数组元素… ……………………………………………………………………  20
3.4.3  删除数组元素… ……………………………………………………………………  21
3.4.4  数组相加… …………………………………………………………………………  22
3.4.5  查找元素的序号… …………………………………………………………………  22
3.4.6  将数组转换成字符串… ……………………………………………………………  23
04  对话框.............................................................................................24
4.1  HTML 基础.................................................................................................  24
4.2  嵌入JavaScript 代码..................................................................................  25
4.3  对话框........................................................................................................  27
4.3.1  输入对话框… ………………………………………………………………………  27
4.3.2  确定对话框… ………………………………………………………………………  29
4.3.3  if 语句… ……………………………………………………………………………  31
4.3.4  警告对话框… ………………………………………………………………………  32
4.4  DOM..........................................................................................................  33
4.4.1  用ID 标识元素………………………………………………………………………  33
4.4.2  选中元素… …………………………………………………………………………  34
4.4.3  替换文本内容… ……………………………………………………………………  34
05  绘制国际象棋棋盘.............................................................................37
5.1  canvas 元素...............................................................................................  37
5.2  绘制方块.....................................................................................................  38
5.3  绘制方框.....................................................................................................  39
5.4  绘制棋盘.....................................................................................................  41
5.5  循环结构.....................................................................................................  42
5.5.1  while 语句… …………………………………………………………………………  42
5.5.2  do-while 语句… ……………………………………………………………………  43
5.5.3  for 循环………………………………………………………………………………  44
06  五子棋.............................................................................................48
6.1  基本绘图方式..............................................................................................  48
6.1.1  绘制线条… …………………………………………………………………………  48
6.1.2  填充路径… …………………………………………………………………………  49
6.1.3  绘制圆弧和圆… ……………………………………………………………………  50
6.2  绘制棋盘.....................................................................................................  51
6.3  鼠标交互.....................................................................................................  52
6.4  绘制棋子.....................................................................................................  54
6.5  黑子和白子.................................................................................................  56
6.6  获胜判断.....................................................................................................  59
6.7  函数............................................................................................................  63
6.7.1  函数的形式… ………………………………………………………………………  63
6.7.2  落子函数… …………………………………………………………………………  64
6.7.3  获胜检测函数… ……………………………………………………………………  65
07  弹球游戏..........................................................................................69
7.1  对象............................................................................................................  69
7.2  对象的方法.................................................................................................  70
7.3  定时功能.....................................................................................................  71
7.4  边界判断.....................................................................................................  72
7.5  增加挡板.....................................................................................................  73
7.6  键盘交互.....................................................................................................  74
08  贪吃蛇.............................................................................................78
8.1  构造函数.....................................................................................................  78
8.2  原型方法.....................................................................................................  78
8.3  贪吃蛇游戏的框架.......................................................................................  79
8.4  贪吃蛇的移动..............................................................................................  80
8.5  贪吃蛇的控制..............................................................................................  82
8.6  添加苹果.....................................................................................................  83
8.7  吃苹果........................................................................................................  84
8.8  生成新苹果.................................................................................................  86
8.9  显示分数.....................................................................................................  87
8.9.1  设置文本基线… ……………………………………………………………………  90
8.9.2  设置文本的大小和字体… …………………………………………………………  91
8.10  游戏结束...................................................................................................  93
8.11  碰撞检测...................................................................................................  93
09  拼图游戏........................................................................................100
9.1  显示图片...................................................................................................  100
9.2  图形的变化...............................................................................................  102
9.3  拼图游戏说明............................................................................................  104
9.4  显示局部图片............................................................................................  105
9.5  图片编号...................................................................................................  107
9.6  移动拼图...................................................................................................  108
9.7  打乱拼图...................................................................................................  112
9.8  拼图状态判断............................................................................................  115
10  飞行射击游戏.................................................................................  121
10.1  图片处理.................................................................................................  121
10.2  绘制飞机.................................................................................................  122
10.3  子弹射击.................................................................................................  123
11  游戏引擎........................................................................................  128
11.1  什么是游戏引擎......................................................................................  128
11.2  Quintus 游戏引擎...................................................................................  128
11.3  网页初始化.............................................................................................  129
11.4  场景和精灵.............................................................................................  130
11.5  精灵控制.................................................................................................  132
11.6  调试功能.................................................................................................  133
11.7  GMP 游戏引擎.......................................................................................  135
11.8  js 文件下载.............................................................................................  136
11.9  真·射击游戏..........................................................................................  137
11.10  游戏优化...............................................................................................  144