465 lines
21 KiB
Plaintext
Generated
465 lines
21 KiB
Plaintext
Generated
<!DOCTYPE html>
|
||
<html>
|
||
<head>
|
||
<meta charset="utf-8">
|
||
<title>Go в примерах: Форматирование строк (String Formatting)</title>
|
||
<link rel=stylesheet href="site.css">
|
||
</head>
|
||
<script>
|
||
onkeydown = (e) => {
|
||
|
||
if (e.key == "ArrowLeft") {
|
||
window.location.href = 'string-functions';
|
||
}
|
||
|
||
|
||
if (e.key == "ArrowRight") {
|
||
window.location.href = 'regular-expressions';
|
||
}
|
||
|
||
}
|
||
</script>
|
||
<body>
|
||
<div class="example" id="string-formatting">
|
||
<h2><a href="./">Go в примерах</a>: Форматирование строк (String Formatting)</h2>
|
||
|
||
<table>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Go предлагает отличную поддержку форматирования строк
|
||
с помощью <code>printf</code>. Вот несколько примеров типичных
|
||
задач форматирования строк.</p>
|
||
|
||
</td>
|
||
<td class="code empty leading">
|
||
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
<a href="http://play.golang.org/p/TKe8eifne_2" target="_blank"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
|
||
<div class="highlight"><pre><span class="kn">package</span> <span class="nx">main</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre><span class="kn">import</span> <span class="p">(</span>
|
||
<span class="s">"fmt"</span>
|
||
<span class="s">"os"</span>
|
||
<span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre><span class="kd">type</span> <span class="nx">point</span> <span class="kd">struct</span> <span class="p">{</span>
|
||
<span class="nx">x</span><span class="p">,</span> <span class="nx">y</span> <span class="kt">int</span>
|
||
<span class="p">}</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">main</span><span class="p">()</span> <span class="p">{</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Go предлагает несколько “глаголов” созданных для
|
||
форматирования общих Go значений. Например,
|
||
это выведет инстанс нашей <code>point</code> структуры.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">p</span> <span class="o">:=</span> <span class="nx">point</span><span class="p">{</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">}</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%v\n"</span><span class="p">,</span> <span class="nx">p</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Если значение является структурой, запись <code>%+v</code>
|
||
выведет названия полей структуры.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%+v\n"</span><span class="p">,</span> <span class="nx">p</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Вариант <code>%#v</code> печатает синтаксическое представление
|
||
Go, то есть фрагмент исходного кода, который будет
|
||
генерировать это значение.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%#v\n"</span><span class="p">,</span> <span class="nx">p</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Для вывода типа значения, используйте <code>%T</code>.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%T\n"</span><span class="p">,</span> <span class="nx">p</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Форматирование логических значений не вызывает затруднений.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%t\n"</span><span class="p">,</span> <span class="kc">true</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Возможно большое количество опций для форматирования
|
||
целых чисел. Используйте <code>%d</code> для стандартного,
|
||
десятеричного вывода.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%d\n"</span><span class="p">,</span> <span class="mi">123</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Бинарный вывод</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%b\n"</span><span class="p">,</span> <span class="mi">14</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Вывод символа, соответсвующего заданному числу.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%c\n"</span><span class="p">,</span> <span class="mi">33</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p><code>%x</code> - шестнадцатиричное значение.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%x\n"</span><span class="p">,</span> <span class="mi">456</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Так же есть несколько вариантов форматирования
|
||
чисел с плавающей точкой. Стандартный вывод <code>%f</code>.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%f\n"</span><span class="p">,</span> <span class="mf">78.9</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p><code>%e</code> и <code>%E</code> приводит числло с плавающей точкой
|
||
к экспоненциальному представлению.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%e\n"</span><span class="p">,</span> <span class="mf">123400000.0</span><span class="p">)</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%E\n"</span><span class="p">,</span> <span class="mf">123400000.0</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Для стандартного вывода строк используйте <code>%s</code>.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%s\n"</span><span class="p">,</span> <span class="s">"\"string\""</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Для двойных ковычек как в исходниках Go, используйте <code>%q</code>.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%q\n"</span><span class="p">,</span> <span class="s">"\"string\""</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Так же как и с целочисленными ранее, <code>%x</code> отображает
|
||
строку в виде шестнадцатеричного исчисления, с двумя
|
||
символами вывода за каждый байт ввода.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%x\n"</span><span class="p">,</span> <span class="s">"hex this"</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Чтобы вывести ссылку на указатель, используйте <code>%p</code>.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"%p\n"</span><span class="p">,</span> <span class="o">&</span><span class="nx">p</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>При форматировании чисел вам часто захочется
|
||
контролировать ширину и точность получаемого значения.
|
||
Чтобы указать ширину целого числа, используйте
|
||
число после <code>%</code>. По-умолчанию результат будет
|
||
выровнен по правому краю и дополнен пробелами.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"|%6d|%6d|\n"</span><span class="p">,</span> <span class="mi">12</span><span class="p">,</span> <span class="mi">345</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Вы также можете указать ширину чисел с плавающей точкой,
|
||
также вы можете ограничить десятичную точность
|
||
одновременно с помощью синтаксиса <code>ширина.точность</code>.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"|%6.2f|%6.2f|\n"</span><span class="p">,</span> <span class="mf">1.2</span><span class="p">,</span> <span class="mf">3.45</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Для выравнивания по левому краю используйте флаг <code>-</code>.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"|%-6.2f|%-6.2f|\n"</span><span class="p">,</span> <span class="mf">1.2</span><span class="p">,</span> <span class="mf">3.45</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Вы также можете контролировать ширину при форматировании
|
||
строк, особенно для обеспечения их выравнивания в табличном
|
||
выводе. Стандартное выравнивание по правому краю.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"|%6s|%6s|\n"</span><span class="p">,</span> <span class="s">"foo"</span><span class="p">,</span> <span class="s">"b"</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Для выравнивания по левому краю используйте флаг <code>-</code>.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Printf</span><span class="p">(</span><span class="s">"|%-6s|%-6s|\n"</span><span class="p">,</span> <span class="s">"foo"</span><span class="p">,</span> <span class="s">"b"</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>До сих пор мы видели <code>Printf</code>, который печатает
|
||
отформатированную строку в <code>os.Stdout</code>. <code>Sprintf</code>
|
||
форматирует и возвращает строку, нигде не печатая.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">s</span> <span class="o">:=</span> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Sprintf</span><span class="p">(</span><span class="s">"a %s"</span><span class="p">,</span> <span class="s">"string"</span><span class="p">)</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">s</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Вы можете отформатировать+вывести в <code>io.Writers</code>, используя
|
||
<code>Fprintf</code>.</p>
|
||
|
||
</td>
|
||
<td class="code">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Fprintf</span><span class="p">(</span><span class="nx">os</span><span class="p">.</span><span class="nx">Stderr</span><span class="p">,</span> <span class="s">"an %s\n"</span><span class="p">,</span> <span class="s">"error"</span><span class="p">)</span>
|
||
<span class="p">}</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
</table>
|
||
|
||
<table>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
|
||
</td>
|
||
<td class="code">
|
||
|
||
<div class="highlight"><pre><span class="gp">$</span> go run string-formatting.go
|
||
<span class="go">{1 2}</span>
|
||
<span class="go">{x:1 y:2}</span>
|
||
<span class="go">main.point{x:1, y:2}</span>
|
||
<span class="go">main.point</span>
|
||
<span class="go">true</span>
|
||
<span class="go">123</span>
|
||
<span class="go">1110</span>
|
||
<span class="go">!</span>
|
||
<span class="go">1c8</span>
|
||
<span class="go">78.900000</span>
|
||
<span class="go">1.234000e+08</span>
|
||
<span class="go">1.234000E+08</span>
|
||
<span class="go">"string"</span>
|
||
<span class="go">"\"string\""</span>
|
||
<span class="go">6865782074686973</span>
|
||
<span class="go">0x42135100</span>
|
||
<span class="go">| 12| 345|</span>
|
||
<span class="go">| 1.20| 3.45|</span>
|
||
<span class="go">|1.20 |3.45 |</span>
|
||
<span class="go">| foo| b|</span>
|
||
<span class="go">|foo |b |</span>
|
||
<span class="go">a string</span>
|
||
<span class="go">an error</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
</table>
|
||
|
||
|
||
<p class="next">
|
||
Следующий пример: <a href="regular-expressions">Регулярные выражения (Regular Expressions)</a>.
|
||
</p>
|
||
|
||
<p class="footer">
|
||
by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> | <a href="https://github.com/mmcgrana/gobyexample/blob/master/examples/string-formatting">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
|
||
<br/>
|
||
переведено Nick S. | <a href="https://github.com/badkaktus/gobyexample">исходники</a>
|
||
</p>
|
||
</div>
|
||
<script>
|
||
var codeLines = [];
|
||
codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import (\u000A \"fmt\"\u000A \"os\"\u000A)\u000A');codeLines.push('type point struct {\u000A x, y int\u000A}\u000A');codeLines.push('func main() {\u000A');codeLines.push(' p := point{1, 2}\u000A fmt.Printf(\"%v\\n\", p)\u000A');codeLines.push(' fmt.Printf(\"%+v\\n\", p)\u000A');codeLines.push(' fmt.Printf(\"%#v\\n\", p)\u000A');codeLines.push(' fmt.Printf(\"%T\\n\", p)\u000A');codeLines.push(' fmt.Printf(\"%t\\n\", true)\u000A');codeLines.push(' fmt.Printf(\"%d\\n\", 123)\u000A');codeLines.push(' fmt.Printf(\"%b\\n\", 14)\u000A');codeLines.push(' fmt.Printf(\"%c\\n\", 33)\u000A');codeLines.push(' fmt.Printf(\"%x\\n\", 456)\u000A');codeLines.push(' fmt.Printf(\"%f\\n\", 78.9)\u000A');codeLines.push(' fmt.Printf(\"%e\\n\", 123400000.0)\u000A fmt.Printf(\"%E\\n\", 123400000.0)\u000A');codeLines.push(' fmt.Printf(\"%s\\n\", \"\\\"string\\\"\")\u000A');codeLines.push(' fmt.Printf(\"%q\\n\", \"\\\"string\\\"\")\u000A');codeLines.push(' fmt.Printf(\"%x\\n\", \"hex this\")\u000A');codeLines.push(' fmt.Printf(\"%p\\n\", &p)\u000A');codeLines.push(' fmt.Printf(\"|%6d|%6d|\\n\", 12, 345)\u000A');codeLines.push(' fmt.Printf(\"|%6.2f|%6.2f|\\n\", 1.2, 3.45)\u000A');codeLines.push(' fmt.Printf(\"|%-6.2f|%-6.2f|\\n\", 1.2, 3.45)\u000A');codeLines.push(' fmt.Printf(\"|%6s|%6s|\\n\", \"foo\", \"b\")\u000A');codeLines.push(' fmt.Printf(\"|%-6s|%-6s|\\n\", \"foo\", \"b\")\u000A');codeLines.push(' s := fmt.Sprintf(\"a %s\", \"string\")\u000A fmt.Println(s)\u000A');codeLines.push(' fmt.Fprintf(os.Stderr, \"an %s\\n\", \"error\")\u000A}\u000A');codeLines.push('');
|
||
</script>
|
||
<script src="site.js" async></script>
|
||
</body>
|
||
</html>
|