-
Notifications
You must be signed in to change notification settings - Fork 8
/
structs.html
269 lines (207 loc) · 10.7 KB
/
structs.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Go by Example 中文版: 结构体</title>
<link rel=stylesheet href="site.css">
</head>
<script>
onkeydown = (e) => {
if (e.key == "ArrowLeft") {
window.location.href = 'strings-and-runes';
}
if (e.key == "ArrowRight") {
window.location.href = 'methods';
}
}
</script>
<body>
<div class="example" id="structs">
<h2><a href="./">Go by Example 中文版</a>: 结构体</h2>
<table>
<tr>
<td class="docs">
<p>Go 的<em>结构体(struct)</em> 是带类型的字段(fields)集合。
这在组织数据时非常有用。</p>
</td>
<td class="code empty leading">
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<a href="https://play.studygolang.com/p/VSQ535HKQj2"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
<pre class="chroma"><span class="kn">package</span> <span class="nx">main</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<pre class="chroma"><span class="kn">import</span> <span class="s">"fmt"</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>这里的 <code>person</code> 结构体包含了 <code>name</code> 和 <code>age</code> 两个字段。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="kd">type</span> <span class="nx">person</span> <span class="kd">struct</span> <span class="p">{</span>
<span class="nx">name</span> <span class="kt">string</span>
<span class="nx">age</span> <span class="kt">int</span>
<span class="p">}</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p><code>newPerson</code> 使用给定的名字构造一个新的 person 结构体.</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="kd">func</span> <span class="nf">newPerson</span><span class="p">(</span><span class="nx">name</span> <span class="kt">string</span><span class="p">)</span> <span class="o">*</span><span class="nx">person</span> <span class="p">{</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>您可以安全地返回指向局部变量的指针，
因为局部变量将在函数的作用域中继续存在。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">p</span> <span class="o">:=</span> <span class="nx">person</span><span class="p">{</span><span class="nx">name</span><span class="p">:</span> <span class="nx">name</span><span class="p">}</span>
<span class="nx">p</span><span class="p">.</span><span class="nx">age</span> <span class="p">=</span> <span class="mi">42</span>
<span class="k">return</span> <span class="o">&</span><span class="nx">p</span>
<span class="p">}</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<pre class="chroma"><span class="kd">func</span> <span class="nf">main</span><span class="p">()</span> <span class="p">{</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>使用这个语法创建新的结构体元素。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">person</span><span class="p">{</span><span class="s">"Bob"</span><span class="p">,</span> <span class="mi">20</span><span class="p">})</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>你可以在初始化一个结构体元素时指定字段名字。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">person</span><span class="p">{</span><span class="nx">name</span><span class="p">:</span> <span class="s">"Alice"</span><span class="p">,</span> <span class="nx">age</span><span class="p">:</span> <span class="mi">30</span><span class="p">})</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>省略的字段将被初始化为零值。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">person</span><span class="p">{</span><span class="nx">name</span><span class="p">:</span> <span class="s">"Fred"</span><span class="p">})</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p><code>&</code> 前缀生成一个结构体指针。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="o">&</span><span class="nx">person</span><span class="p">{</span><span class="nx">name</span><span class="p">:</span> <span class="s">"Ann"</span><span class="p">,</span> <span class="nx">age</span><span class="p">:</span> <span class="mi">40</span><span class="p">})</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>在构造函数中封装创建新的结构实例是一种习惯用法</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nf">newPerson</span><span class="p">(</span><span class="s">"Jon"</span><span class="p">))</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>使用<code>.</code>来访问结构体字段。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">s</span> <span class="o">:=</span> <span class="nx">person</span><span class="p">{</span><span class="nx">name</span><span class="p">:</span> <span class="s">"Sean"</span><span class="p">,</span> <span class="nx">age</span><span class="p">:</span> <span class="mi">50</span><span class="p">}</span>
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">s</span><span class="p">.</span><span class="nx">name</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>也可以对结构体指针使用<code>.</code> - 指针会被自动解引用。</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">sp</span> <span class="o">:=</span> <span class="o">&</span><span class="nx">s</span>
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">sp</span><span class="p">.</span><span class="nx">age</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>结构体是可变(mutable)的。</p>
</td>
<td class="code">
<pre class="chroma">
<span class="nx">sp</span><span class="p">.</span><span class="nx">age</span> <span class="p">=</span> <span class="mi">51</span>
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">sp</span><span class="p">.</span><span class="nx">age</span><span class="p">)</span>
<span class="p">}</span>
</pre>
</td>
</tr>
</table>
<table>
<tr>
<td class="docs">
</td>
<td class="code">
<pre class="chroma"><span class="gp">$</span> go run structs.go
<span class="go">{Bob 20}
</span><span class="go">{Alice 30}
</span><span class="go">{Fred 0}
</span><span class="go">&{Ann 40}
</span><span class="go">&{Jon 42}
</span><span class="go">Sean
</span><span class="go">50
</span><span class="go">51</span></pre>
</td>
</tr>
</table>
<p class="next">
下一个例子: <a href="methods">方法</a>
</p>
<p class="footer">
<a href="https://twitter.com/mmcgrana">@mmcgrana</a> 和<a href="https://eli.thegreenplace.net">Eli Bendersky</a>编写 | <a href="https://github.com/gobyexample-cn">gobyexample-cn</a> 翻译 | <a href="https://github.com/gobyexample-cn/gobyexample/issues">反馈</a> | <a href="https://github.com/gobyexample-cn/gobyexample">源码</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a> </p>
</p>
</div>
<script>
var codeLines = [];
codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import \"fmt\"\u000A');codeLines.push('type person struct {\u000A name string\u000A age int\u000A}\u000A');codeLines.push('func newPerson(name string) *person {\u000A');codeLines.push(' p :\u003D person{name: name}\u000A p.age \u003D 42\u000A return \u0026p\u000A}\u000A');codeLines.push('func main() {\u000A');codeLines.push(' fmt.Println(person{\"Bob\", 20})\u000A');codeLines.push(' fmt.Println(person{name: \"Alice\", age: 30})\u000A');codeLines.push(' fmt.Println(person{name: \"Fred\"})\u000A');codeLines.push(' fmt.Println(\u0026person{name: \"Ann\", age: 40})\u000A');codeLines.push(' fmt.Println(newPerson(\"Jon\"))\u000A');codeLines.push(' s :\u003D person{name: \"Sean\", age: 50}\u000A fmt.Println(s.name)\u000A');codeLines.push(' sp :\u003D \u0026s\u000A fmt.Println(sp.age)\u000A');codeLines.push(' sp.age \u003D 51\u000A fmt.Println(sp.age)\u000A}\u000A');codeLines.push('');
</script>
<script src="site.js" async></script>
</body>
</html>