gopl-zh.github.com/ch6/ch6-04.html

2170 lines
66 KiB
HTML
Raw Normal View History

2015-12-09 07:57:17 +00:00
<!DOCTYPE HTML>
<html lang="zh-tw" >
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<title>方法值和方法錶達式 | Go编程语言</title>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<meta name="description" content="">
<meta name="generator" content="GitBook 2.5.2">
<meta name="HandheldFriendly" content="true"/>
<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black">
<link rel="apple-touch-icon-precomposed" sizes="152x152" href="../gitbook/images/apple-touch-icon-precomposed-152.png">
<link rel="shortcut icon" href="../gitbook/images/favicon.ico" type="image/x-icon">
<link rel="stylesheet" href="../gitbook/style.css">
<link rel="stylesheet" href="../gitbook/plugins/gitbook-plugin-highlight/website.css">
<link rel="stylesheet" href="../gitbook/plugins/gitbook-plugin-search/search.css">
<link rel="stylesheet" href="../gitbook/plugins/gitbook-plugin-fontsettings/website.css">
<link rel="next" href="../ch6/ch6-05.html" />
<link rel="prev" href="../ch6/ch6-03.html" />
</head>
<body>
<div class="book" data-level="6.4" data-chapter-title="方法值和方法錶達式" data-filepath="ch6/ch6-04.md" data-basepath=".." data-revision="Wed Dec 09 2015 15:54:13 GMT+0800 (中国标准时间)">
<div class="book-summary">
<nav role="navigation">
<ul class="summary">
<li class="chapter " data-level="0" data-path="index.html">
<a href="../index.html">
<i class="fa fa-check"></i>
前言
</a>
<ul class="articles">
<li class="chapter " data-level="0.1" data-path="ch0/ch0-01.html">
<a href="../ch0/ch0-01.html">
<i class="fa fa-check"></i>
<b>0.1.</b>
Go語言起源
</a>
</li>
<li class="chapter " data-level="0.2" data-path="ch0/ch0-02.html">
<a href="../ch0/ch0-02.html">
<i class="fa fa-check"></i>
<b>0.2.</b>
Go語言項目
</a>
</li>
<li class="chapter " data-level="0.3" data-path="ch0/ch0-03.html">
<a href="../ch0/ch0-03.html">
<i class="fa fa-check"></i>
<b>0.3.</b>
本書的組織
</a>
</li>
<li class="chapter " data-level="0.4" data-path="ch0/ch0-04.html">
<a href="../ch0/ch0-04.html">
<i class="fa fa-check"></i>
<b>0.4.</b>
更多的信息
</a>
</li>
<li class="chapter " data-level="0.5" data-path="ch0/ch0-05.html">
<a href="../ch0/ch0-05.html">
<i class="fa fa-check"></i>
<b>0.5.</b>
緻謝
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="1" data-path="ch1/ch1.html">
<a href="../ch1/ch1.html">
<i class="fa fa-check"></i>
<b>1.</b>
入門
</a>
<ul class="articles">
<li class="chapter " data-level="1.1" data-path="ch1/ch1-01.html">
<a href="../ch1/ch1-01.html">
<i class="fa fa-check"></i>
<b>1.1.</b>
Hello, World
</a>
</li>
<li class="chapter " data-level="1.2" data-path="ch1/ch1-02.html">
<a href="../ch1/ch1-02.html">
<i class="fa fa-check"></i>
<b>1.2.</b>
命令行參數
</a>
</li>
<li class="chapter " data-level="1.3" data-path="ch1/ch1-03.html">
<a href="../ch1/ch1-03.html">
<i class="fa fa-check"></i>
<b>1.3.</b>
査找重復的行
</a>
</li>
<li class="chapter " data-level="1.4" data-path="ch1/ch1-04.html">
<a href="../ch1/ch1-04.html">
<i class="fa fa-check"></i>
<b>1.4.</b>
GIF動畫
</a>
</li>
<li class="chapter " data-level="1.5" data-path="ch1/ch1-05.html">
<a href="../ch1/ch1-05.html">
<i class="fa fa-check"></i>
<b>1.5.</b>
穫取URL
</a>
</li>
<li class="chapter " data-level="1.6" data-path="ch1/ch1-06.html">
<a href="../ch1/ch1-06.html">
<i class="fa fa-check"></i>
<b>1.6.</b>
併髮穫取多個URL
</a>
</li>
<li class="chapter " data-level="1.7" data-path="ch1/ch1-07.html">
<a href="../ch1/ch1-07.html">
<i class="fa fa-check"></i>
<b>1.7.</b>
Web服務
</a>
</li>
<li class="chapter " data-level="1.8" data-path="ch1/ch1-08.html">
<a href="../ch1/ch1-08.html">
<i class="fa fa-check"></i>
<b>1.8.</b>
本章要點
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="2" data-path="ch2/ch2.html">
<a href="../ch2/ch2.html">
<i class="fa fa-check"></i>
<b>2.</b>
程序結構
</a>
<ul class="articles">
<li class="chapter " data-level="2.1" data-path="ch2/ch2-01.html">
<a href="../ch2/ch2-01.html">
<i class="fa fa-check"></i>
<b>2.1.</b>
命名
</a>
</li>
<li class="chapter " data-level="2.2" data-path="ch2/ch2-02.html">
<a href="../ch2/ch2-02.html">
<i class="fa fa-check"></i>
<b>2.2.</b>
聲明
</a>
</li>
<li class="chapter " data-level="2.3" data-path="ch2/ch2-03.html">
<a href="../ch2/ch2-03.html">
<i class="fa fa-check"></i>
<b>2.3.</b>
變量
</a>
</li>
<li class="chapter " data-level="2.4" data-path="ch2/ch2-04.html">
<a href="../ch2/ch2-04.html">
<i class="fa fa-check"></i>
<b>2.4.</b>
賦值
</a>
</li>
<li class="chapter " data-level="2.5" data-path="ch2/ch2-05.html">
<a href="../ch2/ch2-05.html">
<i class="fa fa-check"></i>
<b>2.5.</b>
類型
</a>
</li>
<li class="chapter " data-level="2.6" data-path="ch2/ch2-06.html">
<a href="../ch2/ch2-06.html">
<i class="fa fa-check"></i>
<b>2.6.</b>
包和文件
</a>
</li>
<li class="chapter " data-level="2.7" data-path="ch2/ch2-07.html">
<a href="../ch2/ch2-07.html">
<i class="fa fa-check"></i>
<b>2.7.</b>
作用域
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="3" data-path="ch3/ch3.html">
<a href="../ch3/ch3.html">
<i class="fa fa-check"></i>
<b>3.</b>
基礎數據類型
</a>
<ul class="articles">
<li class="chapter " data-level="3.1" data-path="ch3/ch3-01.html">
<a href="../ch3/ch3-01.html">
<i class="fa fa-check"></i>
<b>3.1.</b>
整型
</a>
</li>
<li class="chapter " data-level="3.2" data-path="ch3/ch3-02.html">
<a href="../ch3/ch3-02.html">
<i class="fa fa-check"></i>
<b>3.2.</b>
浮點數
</a>
</li>
<li class="chapter " data-level="3.3" data-path="ch3/ch3-03.html">
<a href="../ch3/ch3-03.html">
<i class="fa fa-check"></i>
<b>3.3.</b>
復數
</a>
</li>
<li class="chapter " data-level="3.4" data-path="ch3/ch3-04.html">
<a href="../ch3/ch3-04.html">
<i class="fa fa-check"></i>
<b>3.4.</b>
佈爾型
</a>
</li>
<li class="chapter " data-level="3.5" data-path="ch3/ch3-05.html">
<a href="../ch3/ch3-05.html">
<i class="fa fa-check"></i>
<b>3.5.</b>
字符串
</a>
</li>
<li class="chapter " data-level="3.6" data-path="ch3/ch3-06.html">
<a href="../ch3/ch3-06.html">
<i class="fa fa-check"></i>
<b>3.6.</b>
常量
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="4" data-path="ch4/ch4.html">
<a href="../ch4/ch4.html">
<i class="fa fa-check"></i>
<b>4.</b>
復閤數據類型
</a>
<ul class="articles">
<li class="chapter " data-level="4.1" data-path="ch4/ch4-01.html">
<a href="../ch4/ch4-01.html">
<i class="fa fa-check"></i>
<b>4.1.</b>
數組
</a>
</li>
<li class="chapter " data-level="4.2" data-path="ch4/ch4-02.html">
<a href="../ch4/ch4-02.html">
<i class="fa fa-check"></i>
<b>4.2.</b>
切片
</a>
</li>
<li class="chapter " data-level="4.3" data-path="ch4/ch4-03.html">
<a href="../ch4/ch4-03.html">
<i class="fa fa-check"></i>
<b>4.3.</b>
字典
</a>
</li>
<li class="chapter " data-level="4.4" data-path="ch4/ch4-04.html">
<a href="../ch4/ch4-04.html">
<i class="fa fa-check"></i>
<b>4.4.</b>
結構體
</a>
</li>
<li class="chapter " data-level="4.5" data-path="ch4/ch4-05.html">
<a href="../ch4/ch4-05.html">
<i class="fa fa-check"></i>
<b>4.5.</b>
JSON
</a>
</li>
<li class="chapter " data-level="4.6" data-path="ch4/ch4-06.html">
<a href="../ch4/ch4-06.html">
<i class="fa fa-check"></i>
<b>4.6.</b>
文本和HTML模闆
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="5" data-path="ch5/ch5.html">
<a href="../ch5/ch5.html">
<i class="fa fa-check"></i>
<b>5.</b>
函數
</a>
<ul class="articles">
<li class="chapter " data-level="5.1" data-path="ch5/ch5-01.html">
<a href="../ch5/ch5-01.html">
<i class="fa fa-check"></i>
<b>5.1.</b>
函數聲明
</a>
</li>
<li class="chapter " data-level="5.2" data-path="ch5/ch5-02.html">
<a href="../ch5/ch5-02.html">
<i class="fa fa-check"></i>
<b>5.2.</b>
遞歸
</a>
</li>
<li class="chapter " data-level="5.3" data-path="ch5/ch5-03.html">
<a href="../ch5/ch5-03.html">
<i class="fa fa-check"></i>
<b>5.3.</b>
多返迴值
</a>
</li>
<li class="chapter " data-level="5.4" data-path="ch5/ch5-04.html">
<a href="../ch5/ch5-04.html">
<i class="fa fa-check"></i>
<b>5.4.</b>
錯誤
</a>
</li>
<li class="chapter " data-level="5.5" data-path="ch5/ch5-05.html">
<a href="../ch5/ch5-05.html">
<i class="fa fa-check"></i>
<b>5.5.</b>
函數值
</a>
</li>
<li class="chapter " data-level="5.6" data-path="ch5/ch5-06.html">
<a href="../ch5/ch5-06.html">
<i class="fa fa-check"></i>
<b>5.6.</b>
匿名函數
</a>
</li>
<li class="chapter " data-level="5.7" data-path="ch5/ch5-07.html">
<a href="../ch5/ch5-07.html">
<i class="fa fa-check"></i>
<b>5.7.</b>
可變參數
</a>
</li>
<li class="chapter " data-level="5.8" data-path="ch5/ch5-08.html">
<a href="../ch5/ch5-08.html">
<i class="fa fa-check"></i>
<b>5.8.</b>
Deferred函數
</a>
</li>
<li class="chapter " data-level="5.9" data-path="ch5/ch5-09.html">
<a href="../ch5/ch5-09.html">
<i class="fa fa-check"></i>
<b>5.9.</b>
Panic異常
</a>
</li>
<li class="chapter " data-level="5.10" data-path="ch5/ch5-10.html">
<a href="../ch5/ch5-10.html">
<i class="fa fa-check"></i>
<b>5.10.</b>
Recover捕穫異常
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="6" data-path="ch6/ch6.html">
<a href="../ch6/ch6.html">
<i class="fa fa-check"></i>
<b>6.</b>
方法
</a>
<ul class="articles">
<li class="chapter " data-level="6.1" data-path="ch6/ch6-01.html">
<a href="../ch6/ch6-01.html">
<i class="fa fa-check"></i>
<b>6.1.</b>
方法聲明
</a>
</li>
<li class="chapter " data-level="6.2" data-path="ch6/ch6-02.html">
<a href="../ch6/ch6-02.html">
<i class="fa fa-check"></i>
<b>6.2.</b>
基於指鍼對象的方法
</a>
</li>
<li class="chapter " data-level="6.3" data-path="ch6/ch6-03.html">
<a href="../ch6/ch6-03.html">
<i class="fa fa-check"></i>
<b>6.3.</b>
通過嵌入結構體來擴展類型
</a>
</li>
<li class="chapter active" data-level="6.4" data-path="ch6/ch6-04.html">
<a href="../ch6/ch6-04.html">
<i class="fa fa-check"></i>
<b>6.4.</b>
方法值和方法錶達式
</a>
</li>
<li class="chapter " data-level="6.5" data-path="ch6/ch6-05.html">
<a href="../ch6/ch6-05.html">
<i class="fa fa-check"></i>
<b>6.5.</b>
示例: Bit數組
</a>
</li>
<li class="chapter " data-level="6.6" data-path="ch6/ch6-06.html">
<a href="../ch6/ch6-06.html">
<i class="fa fa-check"></i>
<b>6.6.</b>
封裝
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="7" data-path="ch7/ch7.html">
<a href="../ch7/ch7.html">
<i class="fa fa-check"></i>
<b>7.</b>
接口
</a>
<ul class="articles">
<li class="chapter " data-level="7.1" data-path="ch7/ch7-01.html">
<a href="../ch7/ch7-01.html">
<i class="fa fa-check"></i>
<b>7.1.</b>
接口是閤約
</a>
</li>
<li class="chapter " data-level="7.2" data-path="ch7/ch7-02.html">
<a href="../ch7/ch7-02.html">
<i class="fa fa-check"></i>
<b>7.2.</b>
接口類型
</a>
</li>
<li class="chapter " data-level="7.3" data-path="ch7/ch7-03.html">
<a href="../ch7/ch7-03.html">
<i class="fa fa-check"></i>
<b>7.3.</b>
實現接口的條件
</a>
</li>
<li class="chapter " data-level="7.4" data-path="ch7/ch7-04.html">
<a href="../ch7/ch7-04.html">
<i class="fa fa-check"></i>
<b>7.4.</b>
flag.Value接口
</a>
</li>
<li class="chapter " data-level="7.5" data-path="ch7/ch7-05.html">
<a href="../ch7/ch7-05.html">
<i class="fa fa-check"></i>
<b>7.5.</b>
接口值
</a>
</li>
<li class="chapter " data-level="7.6" data-path="ch7/ch7-06.html">
<a href="../ch7/ch7-06.html">
<i class="fa fa-check"></i>
<b>7.6.</b>
sort.Interface接口
</a>
</li>
<li class="chapter " data-level="7.7" data-path="ch7/ch7-07.html">
<a href="../ch7/ch7-07.html">
<i class="fa fa-check"></i>
<b>7.7.</b>
http.Handler接口
</a>
</li>
<li class="chapter " data-level="7.8" data-path="ch7/ch7-08.html">
<a href="../ch7/ch7-08.html">
<i class="fa fa-check"></i>
<b>7.8.</b>
error接口
</a>
</li>
<li class="chapter " data-level="7.9" data-path="ch7/ch7-09.html">
<a href="../ch7/ch7-09.html">
<i class="fa fa-check"></i>
<b>7.9.</b>
示例: 錶達式求值
</a>
</li>
<li class="chapter " data-level="7.10" data-path="ch7/ch7-10.html">
<a href="../ch7/ch7-10.html">
<i class="fa fa-check"></i>
<b>7.10.</b>
類型斷言
</a>
</li>
<li class="chapter " data-level="7.11" data-path="ch7/ch7-11.html">
<a href="../ch7/ch7-11.html">
<i class="fa fa-check"></i>
<b>7.11.</b>
基於類型斷言識彆錯誤類型
</a>
</li>
<li class="chapter " data-level="7.12" data-path="ch7/ch7-12.html">
<a href="../ch7/ch7-12.html">
<i class="fa fa-check"></i>
<b>7.12.</b>
通過類型斷言査詢接口
</a>
</li>
<li class="chapter " data-level="7.13" data-path="ch7/ch7-13.html">
<a href="../ch7/ch7-13.html">
<i class="fa fa-check"></i>
<b>7.13.</b>
類型分支
</a>
</li>
<li class="chapter " data-level="7.14" data-path="ch7/ch7-14.html">
<a href="../ch7/ch7-14.html">
<i class="fa fa-check"></i>
<b>7.14.</b>
示例: 基於標記的XML解碼
</a>
</li>
<li class="chapter " data-level="7.15" data-path="ch7/ch7-15.html">
<a href="../ch7/ch7-15.html">
<i class="fa fa-check"></i>
<b>7.15.</b>
補充幾點
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="8" data-path="ch8/ch8.html">
<a href="../ch8/ch8.html">
<i class="fa fa-check"></i>
<b>8.</b>
Goroutines和Channels
</a>
<ul class="articles">
<li class="chapter " data-level="8.1" data-path="ch8/ch8-01.html">
<a href="../ch8/ch8-01.html">
<i class="fa fa-check"></i>
<b>8.1.</b>
Goroutines
</a>
</li>
<li class="chapter " data-level="8.2" data-path="ch8/ch8-02.html">
<a href="../ch8/ch8-02.html">
<i class="fa fa-check"></i>
<b>8.2.</b>
示例: 併髮的Clock服務
</a>
</li>
<li class="chapter " data-level="8.3" data-path="ch8/ch8-03.html">
<a href="../ch8/ch8-03.html">
<i class="fa fa-check"></i>
<b>8.3.</b>
示例: 併髮的Echo服務
</a>
</li>
<li class="chapter " data-level="8.4" data-path="ch8/ch8-04.html">
<a href="../ch8/ch8-04.html">
<i class="fa fa-check"></i>
<b>8.4.</b>
Channels
</a>
</li>
<li class="chapter " data-level="8.5" data-path="ch8/ch8-05.html">
<a href="../ch8/ch8-05.html">
<i class="fa fa-check"></i>
<b>8.5.</b>
併行的循環
</a>
</li>
<li class="chapter " data-level="8.6" data-path="ch8/ch8-06.html">
<a href="../ch8/ch8-06.html">
<i class="fa fa-check"></i>
<b>8.6.</b>
示例: 併髮的Web爬蟲
</a>
</li>
<li class="chapter " data-level="8.7" data-path="ch8/ch8-07.html">
<a href="../ch8/ch8-07.html">
<i class="fa fa-check"></i>
<b>8.7.</b>
基於select的多路復用
</a>
</li>
<li class="chapter " data-level="8.8" data-path="ch8/ch8-08.html">
<a href="../ch8/ch8-08.html">
<i class="fa fa-check"></i>
<b>8.8.</b>
示例: 併髮的字典遍歷
</a>
</li>
<li class="chapter " data-level="8.9" data-path="ch8/ch8-09.html">
<a href="../ch8/ch8-09.html">
<i class="fa fa-check"></i>
<b>8.9.</b>
併髮的退齣
</a>
</li>
<li class="chapter " data-level="8.10" data-path="ch8/ch8-10.html">
<a href="../ch8/ch8-10.html">
<i class="fa fa-check"></i>
<b>8.10.</b>
示例: 聊天服務
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="9" data-path="ch9/ch9.html">
<a href="../ch9/ch9.html">
<i class="fa fa-check"></i>
<b>9.</b>
基於共享變量的併髮
</a>
<ul class="articles">
<li class="chapter " data-level="9.1" data-path="ch9/ch9-01.html">
<a href="../ch9/ch9-01.html">
<i class="fa fa-check"></i>
<b>9.1.</b>
競爭條件
</a>
</li>
<li class="chapter " data-level="9.2" data-path="ch9/ch9-02.html">
<a href="../ch9/ch9-02.html">
<i class="fa fa-check"></i>
<b>9.2.</b>
sync.Mutex互斥鎖
</a>
</li>
<li class="chapter " data-level="9.3" data-path="ch9/ch9-03.html">
<a href="../ch9/ch9-03.html">
<i class="fa fa-check"></i>
<b>9.3.</b>
sync.RWMutex讀寫鎖
</a>
</li>
<li class="chapter " data-level="9.4" data-path="ch9/ch9-04.html">
<a href="../ch9/ch9-04.html">
<i class="fa fa-check"></i>
<b>9.4.</b>
內存衕步
</a>
</li>
<li class="chapter " data-level="9.5" data-path="ch9/ch9-05.html">
<a href="../ch9/ch9-05.html">
<i class="fa fa-check"></i>
<b>9.5.</b>
sync.Once初始化
</a>
</li>
<li class="chapter " data-level="9.6" data-path="ch9/ch9-06.html">
<a href="../ch9/ch9-06.html">
<i class="fa fa-check"></i>
<b>9.6.</b>
競爭條件檢測
</a>
</li>
<li class="chapter " data-level="9.7" data-path="ch9/ch9-07.html">
<a href="../ch9/ch9-07.html">
<i class="fa fa-check"></i>
<b>9.7.</b>
示例: 併髮的非阻塞緩存
</a>
</li>
<li class="chapter " data-level="9.8" data-path="ch9/ch9-08.html">
<a href="../ch9/ch9-08.html">
<i class="fa fa-check"></i>
<b>9.8.</b>
Goroutines和綫程
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="10" data-path="ch10/ch10.html">
<a href="../ch10/ch10.html">
<i class="fa fa-check"></i>
<b>10.</b>
包和工具
</a>
<ul class="articles">
<li class="chapter " data-level="10.1" data-path="ch10/ch10-01.html">
<a href="../ch10/ch10-01.html">
<i class="fa fa-check"></i>
<b>10.1.</b>
簡介
</a>
</li>
<li class="chapter " data-level="10.2" data-path="ch10/ch10-02.html">
<a href="../ch10/ch10-02.html">
<i class="fa fa-check"></i>
<b>10.2.</b>
導入路徑
</a>
</li>
<li class="chapter " data-level="10.3" data-path="ch10/ch10-03.html">
<a href="../ch10/ch10-03.html">
<i class="fa fa-check"></i>
<b>10.3.</b>
包聲明
</a>
</li>
<li class="chapter " data-level="10.4" data-path="ch10/ch10-04.html">
<a href="../ch10/ch10-04.html">
<i class="fa fa-check"></i>
<b>10.4.</b>
導入聲明
</a>
</li>
<li class="chapter " data-level="10.5" data-path="ch10/ch10-05.html">
<a href="../ch10/ch10-05.html">
<i class="fa fa-check"></i>
<b>10.5.</b>
匿名導入
</a>
</li>
<li class="chapter " data-level="10.6" data-path="ch10/ch10-06.html">
<a href="../ch10/ch10-06.html">
<i class="fa fa-check"></i>
<b>10.6.</b>
包和命名
</a>
</li>
<li class="chapter " data-level="10.7" data-path="ch10/ch10-07.html">
<a href="../ch10/ch10-07.html">
<i class="fa fa-check"></i>
<b>10.7.</b>
工具
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="11" data-path="ch11/ch11.html">
<a href="../ch11/ch11.html">
<i class="fa fa-check"></i>
<b>11.</b>
測試
</a>
<ul class="articles">
<li class="chapter " data-level="11.1" data-path="ch11/ch11-01.html">
<a href="../ch11/ch11-01.html">
<i class="fa fa-check"></i>
<b>11.1.</b>
go test
</a>
</li>
<li class="chapter " data-level="11.2" data-path="ch11/ch11-02.html">
<a href="../ch11/ch11-02.html">
<i class="fa fa-check"></i>
<b>11.2.</b>
測試函數
</a>
</li>
<li class="chapter " data-level="11.3" data-path="ch11/ch11-03.html">
<a href="../ch11/ch11-03.html">
<i class="fa fa-check"></i>
<b>11.3.</b>
測試覆蓋率
</a>
</li>
<li class="chapter " data-level="11.4" data-path="ch11/ch11-04.html">
<a href="../ch11/ch11-04.html">
<i class="fa fa-check"></i>
<b>11.4.</b>
基準測試
</a>
</li>
<li class="chapter " data-level="11.5" data-path="ch11/ch11-05.html">
<a href="../ch11/ch11-05.html">
<i class="fa fa-check"></i>
<b>11.5.</b>
剖析
</a>
</li>
<li class="chapter " data-level="11.6" data-path="ch11/ch11-06.html">
<a href="../ch11/ch11-06.html">
<i class="fa fa-check"></i>
<b>11.6.</b>
示例函數
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="12" data-path="ch12/ch12.html">
<a href="../ch12/ch12.html">
<i class="fa fa-check"></i>
<b>12.</b>
反射
</a>
<ul class="articles">
<li class="chapter " data-level="12.1" data-path="ch12/ch12-01.html">
<a href="../ch12/ch12-01.html">
<i class="fa fa-check"></i>
<b>12.1.</b>
為何需要反射?
</a>
</li>
<li class="chapter " data-level="12.2" data-path="ch12/ch12-02.html">
<a href="../ch12/ch12-02.html">
<i class="fa fa-check"></i>
<b>12.2.</b>
reflect.Type和reflect.Value
</a>
</li>
<li class="chapter " data-level="12.3" data-path="ch12/ch12-03.html">
<a href="../ch12/ch12-03.html">
<i class="fa fa-check"></i>
<b>12.3.</b>
Display遞歸打印
</a>
</li>
<li class="chapter " data-level="12.4" data-path="ch12/ch12-04.html">
<a href="../ch12/ch12-04.html">
<i class="fa fa-check"></i>
<b>12.4.</b>
示例: 編碼S錶達式
</a>
</li>
<li class="chapter " data-level="12.5" data-path="ch12/ch12-05.html">
<a href="../ch12/ch12-05.html">
<i class="fa fa-check"></i>
<b>12.5.</b>
通過reflect.Value脩改值
</a>
</li>
<li class="chapter " data-level="12.6" data-path="ch12/ch12-06.html">
<a href="../ch12/ch12-06.html">
<i class="fa fa-check"></i>
<b>12.6.</b>
示例: 解碼S錶達式
</a>
</li>
<li class="chapter " data-level="12.7" data-path="ch12/ch12-07.html">
<a href="../ch12/ch12-07.html">
<i class="fa fa-check"></i>
<b>12.7.</b>
穫取結構體字段標識
</a>
</li>
<li class="chapter " data-level="12.8" data-path="ch12/ch12-08.html">
<a href="../ch12/ch12-08.html">
<i class="fa fa-check"></i>
<b>12.8.</b>
顯示一個類型的方法集
</a>
</li>
<li class="chapter " data-level="12.9" data-path="ch12/ch12-09.html">
<a href="../ch12/ch12-09.html">
<i class="fa fa-check"></i>
<b>12.9.</b>
幾點忠告
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="13" data-path="ch13/ch13.html">
<a href="../ch13/ch13.html">
<i class="fa fa-check"></i>
<b>13.</b>
底層編程
</a>
<ul class="articles">
<li class="chapter " data-level="13.1" data-path="ch13/ch13-01.html">
<a href="../ch13/ch13-01.html">
<i class="fa fa-check"></i>
<b>13.1.</b>
unsafe.Sizeof, Alignof 和 Offsetof
</a>
</li>
<li class="chapter " data-level="13.2" data-path="ch13/ch13-02.html">
<a href="../ch13/ch13-02.html">
<i class="fa fa-check"></i>
<b>13.2.</b>
unsafe.Pointer
</a>
</li>
<li class="chapter " data-level="13.3" data-path="ch13/ch13-03.html">
<a href="../ch13/ch13-03.html">
<i class="fa fa-check"></i>
<b>13.3.</b>
示例: 深度相等判斷
</a>
</li>
<li class="chapter " data-level="13.4" data-path="ch13/ch13-04.html">
<a href="../ch13/ch13-04.html">
<i class="fa fa-check"></i>
<b>13.4.</b>
通過cgo調用C代碼
</a>
</li>
<li class="chapter " data-level="13.5" data-path="ch13/ch13-05.html">
<a href="../ch13/ch13-05.html">
<i class="fa fa-check"></i>
<b>13.5.</b>
幾點忠告
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="14" data-path="exercise/ex.html">
<a href="../exercise/ex.html">
<i class="fa fa-check"></i>
<b>14.</b>
習題解答
</a>
<ul class="articles">
<li class="chapter " data-level="14.1" data-path="exercise/ex-ch1.html">
<a href="../exercise/ex-ch1.html">
<i class="fa fa-check"></i>
<b>14.1.</b>
第一章 入門
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="15" data-path="errata.html">
<a href="../errata.html">
<i class="fa fa-check"></i>
<b>15.</b>
勘誤
</a>
</li>
<li class="divider"></li>
<li>
<a href="https://www.gitbook.com" target="blank" class="gitbook-link">
本書使用 GitBook 釋出
</a>
</li>
</ul>
</nav>
</div>
<div class="book-body">
<div class="body-inner">
<div class="book-header" role="navigation">
<!-- Actions Left -->
<!-- Title -->
<h1>
<i class="fa fa-circle-o-notch fa-spin"></i>
<a href="../" >Go编程语言</a>
</h1>
</div>
<div class="page-wrapper" tabindex="-1" role="main">
<div class="page-inner">
<section class="normal" id="section-">
<h2 id="64-&#x65B9;&#x6CD5;&#x503C;&#x548C;&#x65B9;&#x6CD5;&#x9336;&#x9054;&#x5F0F;">6.4. &#x65B9;&#x6CD5;&#x503C;&#x548C;&#x65B9;&#x6CD5;&#x9336;&#x9054;&#x5F0F;</h2>
<p>&#x6211;&#x5011;&#x7D93;&#x5E38;&#x9078;&#x64C7;&#x4E00;&#x500B;&#x65B9;&#x6CD5;&#xFF0C;&#x4F75;&#x4E14;&#x5728;&#x8855;&#x4E00;&#x500B;&#x9336;&#x9054;&#x5F0F;&#x88CF;&#x57F7;&#x884C;&#xFF0C;&#x6BD4;&#x5982;&#x5E38;&#x898B;&#x7684;p.Distance()&#x5F62;&#x5F0F;&#xFF0C;&#x5BE6;&#x969B;&#x4E0A;&#x5C07;&#x5176;&#x5206;&#x6210;&#x5169;&#x6B65;&#x4F86;&#x57F7;&#x884C;&#x4E5F;&#x662F;&#x53EF;&#x80FD;&#x7684;&#x3002;p.Distance&#x53EB;&#x4F5C;&#x201C;&#x9078;&#x64C7;&#x5668;&#x201D;&#xFF0C;&#x9078;&#x64C7;&#x5668;&#x6703;&#x8FD4;&#x8FF4;&#x4E00;&#x500B;&#x65B9;&#x6CD5;&quot;&#x503C;&quot;-&gt;&#x4E00;&#x500B;&#x5C07;&#x65B9;&#x6CD5;(Point.Distance)&#x7D81;&#x5B9A;&#x5230;&#x7279;&#x5B9A;&#x63A5;&#x6536;&#x5668;&#x8B8A;&#x91CF;&#x7684;&#x51FD;&#x6578;&#x3002;&#x9019;&#x500B;&#x51FD;&#x6578;&#x53EF;&#x4EE5;&#x4E0D;&#x901A;&#x904E;&#x6307;&#x5B9A;&#x5176;&#x63A5;&#x6536;&#x5668;&#x537D;&#x53EF;&#x88AB;&#x8ABF;&#x7528;&#xFF1B;&#x537D;&#x8ABF;&#x7528;&#x6642;&#x4E0D;&#x9700;&#x8981;&#x6307;&#x5B9A;&#x63A5;&#x6536;&#x5668;(&#x8B6F;&#x8A3B;&#xFF1A;&#x56E0;&#x70BA;&#x5DF2;&#x7D93;&#x5728;&#x524D;&#x6587;&#x4E2D;&#x6307;&#x5B9A;&#x904E;&#x4E86;)&#xFF0C;&#x96BB;&#x8981;&#x50B3;&#x5165;&#x51FD;&#x6578;&#x7684;&#x53C3;&#x6578;&#x537D;&#x53EF;&#xFF1A;</p>
<pre><code class="lang-go">p := Point{<span class="hljs-number">1</span>, <span class="hljs-number">2</span>}
q := Point{<span class="hljs-number">4</span>, <span class="hljs-number">6</span>}
distanceFromP := p.Distance <span class="hljs-comment">// method value</span>
fmt.Println(distanceFromP(q)) <span class="hljs-comment">// &quot;5&quot;</span>
<span class="hljs-keyword">var</span> origin Point <span class="hljs-comment">// {0, 0}</span>
fmt.Println(distanceFromP(origin)) <span class="hljs-comment">// &quot;2.23606797749979&quot;, ;5</span>
scaleP := p.ScaleBy <span class="hljs-comment">// method value</span>
scaleP(<span class="hljs-number">2</span>) <span class="hljs-comment">// p becomes (2, 4)</span>
scaleP(<span class="hljs-number">3</span>) <span class="hljs-comment">// then (6, 12)</span>
scaleP(<span class="hljs-number">10</span>) <span class="hljs-comment">// then (60, 120)</span>
</code></pre>
<p>&#x5728;&#x4E00;&#x500B;&#x5305;&#x7684;API&#x9700;&#x8981;&#x4E00;&#x500B;&#x51FD;&#x6578;&#x503C;&#x3001;&#x4E14;&#x8ABF;&#x7528;&#x65B9;&#x5E0C;&#x671B;&#x64CD;&#x4F5C;&#x7684;&#x662F;&#x67D0;&#x4E00;&#x500B;&#x7D81;&#x5B9A;&#x4E86;&#x5C0D;&#x8C61;&#x7684;&#x65B9;&#x6CD5;&#x7684;&#x8A71;&#xFF0C;&#x65B9;&#x6CD5;&quot;&#x503C;&quot;&#x6703;&#x975E;&#x5E38;&#x5BE6;&#x7528;(=_=&#x771E;&#x662F;&#x7E5E;)&#x3002;&#x8209;&#x4F8B;&#x4F86;&#x8AAA;&#xFF0C;&#x4E0B;&#x9EAB;&#x4F8B;&#x5B50;&#x4E2D;&#x7684;time.AfterFunc&#x9019;&#x500B;&#x51FD;&#x6578;&#x7684;&#x529F;&#x80FD;&#x662F;&#x5728;&#x6307;&#x5B9A;&#x7684;&#x5EF6;&#x9072;&#x6642;&#x9593;&#x4E4B;&#x5F8C;&#x4F86;&#x57F7;&#x884C;&#x4E00;&#x500B;(&#x8B6F;&#x8A3B;&#xFF1A;&#x53E6;&#x5916;&#x7684;)&#x51FD;&#x6578;&#x3002;&#x4E14;&#x9019;&#x500B;&#x51FD;&#x6578;&#x64CD;&#x4F5C;&#x7684;&#x662F;&#x4E00;&#x500B;Rocket&#x5C0D;&#x8C61;r</p>
<pre><code class="lang-go"><span class="hljs-keyword">type</span> Rocket <span class="hljs-keyword">struct</span> { <span class="hljs-comment">/* ... */</span> }
<span class="hljs-keyword">func</span> (r *Rocket) Launch() { <span class="hljs-comment">/* ... */</span> }
r := <span class="hljs-built_in">new</span>(Rocket)
time.AfterFunc(<span class="hljs-number">10</span> * time.Second, <span class="hljs-keyword">func</span>() { r.Launch() })
</code></pre>
<p>&#x76F4;&#x63A5;&#x7528;&#x65B9;&#x6CD5;&quot;&#x503C;&quot;&#x50B3;&#x5165;AfterFunc&#x7684;&#x8A71;&#x53EF;&#x4EE5;&#x66F4;&#x70BA;&#x7C21;&#x77ED;&#xFF1A;</p>
<pre><code class="lang-go">time.AfterFunc(<span class="hljs-number">10</span> * time.Second, r.Launch)
</code></pre>
<p>&#x8B6F;&#x8A3B;&#xFF1A;&#x7701;&#x6389;&#x4E86;&#x4E0A;&#x9EAB;&#x90A3;&#x500B;&#x4F8B;&#x5B50;&#x88CF;&#x7684;&#x533F;&#x540D;&#x51FD;&#x6578;&#x3002;</p>
<p>&#x548C;&#x65B9;&#x6CD5;&quot;&#x503C;&quot;&#x76F8;&#x95DC;&#x7684;&#x9084;&#x6709;&#x65B9;&#x6CD5;&#x9336;&#x9054;&#x5F0F;&#x3002;&#x7576;&#x8ABF;&#x7528;&#x4E00;&#x500B;&#x65B9;&#x6CD5;&#x6642;&#xFF0C;&#x8207;&#x8ABF;&#x7528;&#x4E00;&#x500B;&#x666E;&#x901A;&#x7684;&#x51FD;&#x6578;&#x76F8;&#x6BD4;&#xFF0C;&#x6211;&#x5011;&#x5FC5;&#x9B1A;&#x8981;&#x7528;&#x9078;&#x64C7;&#x5668;(p.Distance)&#x8A9E;&#x6CD5;&#x4F86;&#x6307;&#x5B9A;&#x65B9;&#x6CD5;&#x7684;&#x63A5;&#x6536;&#x5668;&#x3002;</p>
<p>&#x7576;T&#x662F;&#x4E00;&#x500B;&#x985E;&#x578B;&#x6642;&#xFF0C;&#x65B9;&#x6CD5;&#x9336;&#x9054;&#x5F0F;&#x53EF;&#x80FD;&#x6703;&#x5BEB;&#x4F5C;T.f&#x6216;&#x8005;(*T).f&#xFF0C;&#x6703;&#x8FD4;&#x8FF4;&#x4E00;&#x500B;&#x51FD;&#x6578;&quot;&#x503C;&quot;&#xFF0C;&#x9019;&#x7A2E;&#x51FD;&#x6578;&#x6703;&#x5C07;&#x5176;&#x7B2C;&#x4E00;&#x500B;&#x53C3;&#x6578;&#x7528;&#x4F5C;&#x63A5;&#x6536;&#x5668;&#xFF0C;&#x6240;&#x4EE5;&#x53EF;&#x4EE5;&#x7528;&#x901A;&#x5E38;(&#x8B6F;&#x8A3B;&#xFF1A;&#x4E0D;&#x5BEB;&#x9078;&#x64C7;&#x5668;)&#x7684;&#x65B9;&#x5F0F;&#x4F86;&#x5C0D;&#x5176;&#x9032;&#x884C;&#x8ABF;&#x7528;&#xFF1A;</p>
<pre><code class="lang-go">p := Point{<span class="hljs-number">1</span>, <span class="hljs-number">2</span>}
q := Point{<span class="hljs-number">4</span>, <span class="hljs-number">6</span>}
distance := Point.Distance <span class="hljs-comment">// method expression</span>
<span class="hljs-comment">//&#x8B6F;&#x8A3B;&#xFF1A;&#x9019;&#x500B;Distance&#x5BE6;&#x969B;&#x4E0A;&#x662F;&#x6307;&#x5B9A;&#x4E86;Point&#x5C0D;&#x8C61;&#x70BA;&#x63A5;&#x6536;&#x5668;&#x7684;&#x4E00;&#x500B;&#x65B9;&#x6CD5;func (p Point) Distance()&#xFF0C;&#x4F46;&#x901A;&#x904E;Point.Distance&#x5F97;&#x5230;&#x7684;&#x51FD;&#x6578;&#x9700;&#x8981;&#x6BD4;&#x5BE6;&#x969B;&#x7684;Distance&#x65B9;&#x6CD5;&#x591A;&#x4E00;&#x500B;&#x53C3;&#x6578;&#xFF0C;&#x537D;&#x5176;&#x9700;&#x8981;&#x7528;&#x7B2C;&#x4E00;&#x500B;&#x984D;&#x5916;&#x53C3;&#x6578;&#x6307;&#x5B9A;&#x63A5;&#x6536;&#x5668;&#xFF0C;&#x5F8C;&#x9EAB;&#x6392;&#x5217;Distance&#x65B9;&#x6CD5;&#x7684;&#x53C3;&#x6578;&#x3002;&#x770B;&#x8D77;&#x4F86;&#x672C;&#x66F8;&#x4E2D;&#x51FD;&#x6578;&#x548C;&#x65B9;&#x6CD5;&#x7684;&#x5340;&#x5F46;&#x662F;&#x6307;&#x6709;&#x6C92;&#x6709;&#x63A5;&#x6536;&#x5668;&#xFF0C;&#x800C;&#x4E0D;&#x50CF;&#x5176;&#x4ED6;&#x8A9E;&#x8A00;&#x90A3;&#x6A23;&#x662F;&#x6307;&#x6709;&#x6C92;&#x6709;&#x8FD4;&#x8FF4;&#x503C;&#x3002;</span>
fmt.Println(distance(p, q)) <span class="hljs-comment">// &quot;5&quot;</span>
fmt.Printf(<span class="hljs-string">&quot;%T\n&quot;</span>, distance) <span class="hljs-comment">// &quot;func(Point, Point) float64&quot;</span>
scale := (*Point).ScaleBy
scale(&amp;p, <span class="hljs-number">2</span>)
fmt.Println(p) <span class="hljs-comment">// &quot;{2 4}&quot;</span>
fmt.Printf(<span class="hljs-string">&quot;%T\n&quot;</span>, scale) <span class="hljs-comment">// &quot;func(*Point, float64)&quot;</span>
</code></pre>
<p>&#x7576;&#x4F60;&#x6839;&#x64DA;&#x4E00;&#x500B;&#x8B8A;&#x91CF;&#x4F86;&#x6C7A;&#x5B9A;&#x8ABF;&#x7528;&#x8855;&#x4E00;&#x500B;&#x985E;&#x578B;&#x7684;&#x54EA;&#x500B;&#x51FD;&#x6578;&#x6642;&#xFF0C;&#x65B9;&#x6CD5;&#x9336;&#x9054;&#x5F0F;&#x5C31;&#x986F;&#x5F97;&#x5F88;&#x6709;&#x7528;&#x4E86;&#x3002;&#x4F60;&#x53EF;&#x4EE5;&#x6839;&#x64DA;&#x9078;&#x64C7;&#x4F86;&#x8ABF;&#x7528;&#x63A5;&#x6536;&#x5668;&#x5404;&#x4E0D;&#x76F8;&#x8855;&#x7684;&#x65B9;&#x6CD5;&#x3002;&#x4E0B;&#x9EAB;&#x7684;&#x4F8B;&#x5B50;&#xFF0C;&#x8B8A;&#x91CF;op&#x4EE3;&#x9336;Point&#x985E;&#x578B;&#x7684;addition&#x6216;&#x8005;subtraction&#x65B9;&#x6CD5;&#xFF0C;Path.TranslateBy&#x65B9;&#x6CD5;&#x6703;&#x70BA;&#x5176;Path&#x6578;&#x7D44;&#x4E2D;&#x7684;&#x6BCF;&#x4E00;&#x500B;Point&#x4F86;&#x8ABF;&#x7528;&#x5C0D;&#x61C9;&#x7684;&#x65B9;&#x6CD5;&#xFF1A;</p>
<pre><code class="lang-go"><span class="hljs-keyword">type</span> Point <span class="hljs-keyword">struct</span>{ X, Y <span class="hljs-typename">float64</span> }
<span class="hljs-keyword">func</span> (p Point) Add(q Point) Point { <span class="hljs-keyword">return</span> Point{p.X + q.X, p.Y + q.Y} }
<span class="hljs-keyword">func</span> (p Point) Sub(q Point) Point { <span class="hljs-keyword">return</span> Point{p.X - q.X, p.Y - q.Y} }
<span class="hljs-keyword">type</span> Path []Point
<span class="hljs-keyword">func</span> (path Path) TranslateBy(offset Point, add <span class="hljs-typename">bool</span>) {
<span class="hljs-keyword">var</span> op <span class="hljs-keyword">func</span>(p, q Point) Point
<span class="hljs-keyword">if</span> add {
op = Point.Add
} <span class="hljs-keyword">else</span> {
op = Point.Sub
}
<span class="hljs-keyword">for</span> i := <span class="hljs-keyword">range</span> path {
<span class="hljs-comment">// Call either path[i].Add(offset) or path[i].Sub(offset).</span>
path[i] = op(path[i], offset)
}
}
</code></pre>
</section>
</div>
</div>
</div>
<a href="../ch6/ch6-03.html" class="navigation navigation-prev " aria-label="Previous page: 通過嵌入結構體來擴展類型"><i class="fa fa-angle-left"></i></a>
<a href="../ch6/ch6-05.html" class="navigation navigation-next " aria-label="Next page: 示例: Bit數組"><i class="fa fa-angle-right"></i></a>
</div>
</div>
<script src="../gitbook/app.js"></script>
<script src="../gitbook/plugins/gitbook-plugin-search/lunr.min.js"></script>
<script src="../gitbook/plugins/gitbook-plugin-search/search.js"></script>
<script src="../gitbook/plugins/gitbook-plugin-sharing/buttons.js"></script>
<script src="../gitbook/plugins/gitbook-plugin-fontsettings/buttons.js"></script>
<script>
require(["gitbook"], function(gitbook) {
var config = {"highlight":{},"search":{},"sharing":{"facebook":true,"twitter":true,"google":false,"weibo":false,"instapaper":false,"vk":false,"all":["facebook","google","twitter","weibo","instapaper"]},"fontsettings":{"theme":"white","family":"sans","size":2}};
gitbook.start(config);
});
</script>
</body>
</html>