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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Go by Example မြန်မာဘာသာ: 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 = 'text-templates';
}
}
</script>
<body>
<div class="example" id="string-formatting">
<h2><a href="./">Go by Example မြန်မာဘာသာ</a>: String Formatting</h2>
<table>
<tr>
<td class="docs">
<p>Go က <code>printf</code> ပုံစံမျိုးနဲ့ string formatting အတွက် အထောက်အပံ့ကောင်းကောင်း (excellent support) ပေးထားပါတယ်။
ဒီမှာ ပုံမှန်တွေ့ရတဲ့ string formatting လုပ်ငန်းတွေရဲ့ ဥပမာတချို့ ရှိပါတယ်။</p>
</td>
<td class="code empty leading">
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<a href="https://go.dev/play/p/uHzpaUE5Yl4"><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="p">(</span>
<span class="s">"fmt"</span>
<span class="s">"os"</span>
<span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<pre class="chroma"><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>
</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>Go မှာ အထွေထွေ Go value တွေကို format လုပ်ဖို့ ဒီဇိုင်းဆွဲထားတဲ့
printing “verb” တွေ အများကြီး ရှိပါတယ်။ ဥပမာ၊ ဒါက ကျွန်တော်တို့ရဲ့
<code>point</code> struct တစ်ခုကို print ထုတ်ပါတယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<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="nf">Printf</span><span class="p">(</span><span class="s">"struct1: %v\n"</span><span class="p">,</span> <span class="nx">p</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>Value က struct ဖြစ်နေရင်၊ <code>%+v</code> က
struct ရဲ့ field နာမည်တွေပါ ထည့်သွင်းပါလိမ့်မယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"struct2: %+v\n"</span><span class="p">,</span> <span class="nx">p</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p><code>%#v</code> က value ရဲ့ Go syntax ကိုယ်စားပြုမှုကို print ထုတ်ပါတယ်။
ဆိုလိုတာက အဲဒီ value ကို ထုတ်လုပ်မယ့် source code အပိုင်းအစပါ။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"struct3: %#v\n"</span><span class="p">,</span> <span class="nx">p</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>Value တစ်ခုရဲ့ type ကို print ထုတ်ဖို့ <code>%T</code> ကို သုံးပါ။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"type: %T\n"</span><span class="p">,</span> <span class="nx">p</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>Boolean တွေကို format လုပ်တာ ရိုးရှင်းပါတယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"bool: %t\n"</span><span class="p">,</span> <span class="kc">true</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>Integer တွေကို format လုပ်ဖို့ option အများကြီး ရှိပါတယ်။
ပုံမှန် base-10 format အတွက် <code>%d</code> ကို သုံးပါ။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"int: %d\n"</span><span class="p">,</span> <span class="mi">123</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>ဒါက binary ပုံစံနဲ့ print ထုတ်ပါတယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"bin: %b\n"</span><span class="p">,</span> <span class="mi">14</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>ဒါက ပေးလိုက်တဲ့ integer နဲ့ ကိုက်ညီတဲ့ စာလုံးကို print ထုတ်ပါတယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"char: %c\n"</span><span class="p">,</span> <span class="mi">33</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p><code>%x</code> က hex encoding ပေးပါတယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"hex: %x\n"</span><span class="p">,</span> <span class="mi">456</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>Float တွေအတွက်လည်း formatting option အများကြီး ရှိပါတယ်။
အခြေခံ ဒဿမ formatting အတွက် <code>%f</code> ကို သုံးပါ။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"float1: %f\n"</span><span class="p">,</span> <span class="mf">78.9</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p><code>%e</code> နဲ့ <code>%E</code> က float ကို သိပ္ပံနည်းကျ ရေးနည်း (နည်းနည်း ကွာခြားတဲ့ version နှစ်ခု) နဲ့ format လုပ်ပါတယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"float2: %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="nf">Printf</span><span class="p">(</span><span class="s">"float3: %E\n"</span><span class="p">,</span> <span class="mf">123400000.0</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>အခြေခံ string printing အတွက် <code>%s</code> ကို သုံးပါ။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"str1: %s\n"</span><span class="p">,</span> <span class="s">"\"string\""</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>Go source code မှာလိုမျိုး string တွေကို double-quote လုပ်ဖို့ <code>%q</code> ကို သုံးပါ။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"str2: %q\n"</span><span class="p">,</span> <span class="s">"\"string\""</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>အပေါ်မှာ မြင်ခဲ့ရတဲ့ integer တွေလိုပဲ၊ <code>%x</code> က
string ကို base-16 နဲ့ ဖော်ပြပါတယ်။ Input byte တစ်ခုစီအတွက်
output စာလုံး နှစ်လုံးစီ ထွက်ပါတယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"str3: %x\n"</span><span class="p">,</span> <span class="s">"hex this"</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>Pointer တစ်ခုရဲ့ ကိုယ်စားပြုမှုကို print ထုတ်ဖို့ <code>%p</code> ကို သုံးပါ။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"pointer: %p\n"</span><span class="p">,</span> <span class="o">&</span><span class="nx">p</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p>နံပါတ်တွေကို format လုပ်တဲ့အခါ ထွက်လာမယ့် ဂဏန်းရဲ့
အကျယ်နဲ့ တိကျမှုကို ထိန်းချုပ်ချင်တာ မကြာခဏ လုပ်ချင်ပါလိမ့်မယ်။
Integer တစ်ခုရဲ့ အကျယ်ကို သတ်မှတ်ဖို့ verb ထဲက <code>%</code> နောက်မှာ
နံပါတ်တစ်ခု ထည့်ပါ။ ပုံမှန်အားဖြင့် ရလဒ်က ညာဘက်ကပ်ပြီး
space တွေနဲ့ ဖြည့်ထားပါလိမ့်မယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"width1: |%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>
</td>
</tr>
<tr>
<td class="docs">
<p>နံပါတ်တွေကို format လုပ်တဲ့အခါ ထွက်လာမယ့် ဂဏန်းရဲ့
အကျယ်နဲ့ တိကျမှုကို ထိန်းချုပ်ချင်တာ မကြာခဏ ဖြစ်ပါလိမ့်မယ်။
Integer တစ်ခုရဲ့ အကျယ်ကို သတ်မှတ်ဖို့ verb ထဲက <code>%</code> နောက်မှာ
နံပါတ်တစ်ခု ထည့်ပါ။ ပုံမှန်အားဖြင့် ရလဒ်က ညာဘက်ကပ်ပြီး
space တွေနဲ့ ဖြည့်ထားပါလိမ့်မယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"width2: |%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>
</td>
</tr>
<tr>
<td class="docs">
<p>ဘယ်ဘက်ကပ်ဖို့ <code>-</code> flag ကို သုံးပါ။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"width3: |%-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>
</td>
</tr>
<tr>
<td class="docs">
<p>String တွေကို format လုပ်တဲ့အခါလည်း အကျယ်ကို ထိန်းချုပ်ချင်နိုင်ပါတယ်။
အထူးသဖြင့် ဇယားလို output မှာ တန်းစီအောင် လုပ်ချင်တဲ့အခါပါ။
အခြေခံ ညာဘက်ကပ် အကျယ်အတွက်:</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"width4: |%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>
</td>
</tr>
<tr>
<td class="docs">
<p>ဘယ်ဘက်ကပ်ဖို့ နံပါတ်တွေမှာလိုပဲ <code>-</code> flag ကို သုံးပါ။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">Printf</span><span class="p">(</span><span class="s">"width5: |%-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>
</td>
</tr>
<tr>
<td class="docs">
<p>အခုထိ ကျွန်တော်တို့ <code>Printf</code> ကို မြင်ခဲ့ကြပါတယ်။ သူက
format လုပ်ထားတဲ့ string ကို <code>os.Stdout</code> မှာ print ထုတ်ပါတယ်။
<code>Sprintf</code> ကတော့ string ကို format လုပ်ပြီး ဘယ်နေရာမှာမှ print မထုတ်ဘဲ
ပြန်ပေးပါတယ်။</p>
</td>
<td class="code leading">
<pre class="chroma">
<span class="nx">s</span> <span class="o">:=</span> <span class="nx">fmt</span><span class="p">.</span><span class="nf">Sprintf</span><span class="p">(</span><span class="s">"sprintf: 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="nf">Println</span><span class="p">(</span><span class="nx">s</span><span class="p">)</span>
</pre>
</td>
</tr>
<tr>
<td class="docs">
<p><code>os.Stdout</code> မဟုတ်တဲ့ တခြား <code>io.Writers</code> တွေမှာ format+print လုပ်ချင်ရင်
<code>Fprintf</code> ကို သုံးနိုင်ပါတယ်။</p>
</td>
<td class="code">
<pre class="chroma">
<span class="nx">fmt</span><span class="p">.</span><span class="nf">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">"io: an %s\n"</span><span class="p">,</span> <span class="s">"error"</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 string-formatting.go
<span class="go">struct1: {1 2}
</span><span class="go">struct2: {x:1 y:2}
</span><span class="go">struct3: main.point{x:1, y:2}
</span><span class="go">type: main.point
</span><span class="go">bool: true
</span><span class="go">int: 123
</span><span class="go">bin: 1110
</span><span class="go">char: !
</span><span class="go">hex: 1c8
</span><span class="go">float1: 78.900000
</span><span class="go">float2: 1.234000e+08
</span><span class="go">float3: 1.234000E+08
</span><span class="go">str1: "string"
</span><span class="go">str2: "\"string\""
</span><span class="go">str3: 6865782074686973
</span><span class="go">pointer: 0xc0000ba000
</span><span class="go">width1: | 12| 345|
</span><span class="go">width2: | 1.20| 3.45|
</span><span class="go">width3: |1.20 |3.45 |
</span><span class="go">width4: | foo| b|
</span><span class="go">width5: |foo |b |
</span><span class="go">sprintf: a string
</span><span class="go">io: an error</span></pre>
</td>
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နောက်ဥပမာ: <a href="text-templates">Text Templates</a>.
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by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> နှင့် <a href="https://eli.thegreenplace.net">Eli Bendersky</a> | <a href="https://github.com/mmcgrana/gobyexample">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
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<script>
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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 :\u003D point{1, 2}\u000A fmt.Printf(\"struct1: %v\\n\", p)\u000A');codeLines.push(' fmt.Printf(\"struct2: %+v\\n\", p)\u000A');codeLines.push(' fmt.Printf(\"struct3: %#v\\n\", p)\u000A');codeLines.push(' fmt.Printf(\"type: %T\\n\", p)\u000A');codeLines.push(' fmt.Printf(\"bool: %t\\n\", true)\u000A');codeLines.push(' fmt.Printf(\"int: %d\\n\", 123)\u000A');codeLines.push(' fmt.Printf(\"bin: %b\\n\", 14)\u000A');codeLines.push(' fmt.Printf(\"char: %c\\n\", 33)\u000A');codeLines.push(' fmt.Printf(\"hex: %x\\n\", 456)\u000A');codeLines.push(' fmt.Printf(\"float1: %f\\n\", 78.9)\u000A');codeLines.push(' fmt.Printf(\"float2: %e\\n\", 123400000.0)\u000A fmt.Printf(\"float3: %E\\n\", 123400000.0)\u000A');codeLines.push(' fmt.Printf(\"str1: %s\\n\", \"\\\"string\\\"\")\u000A');codeLines.push(' fmt.Printf(\"str2: %q\\n\", \"\\\"string\\\"\")\u000A');codeLines.push(' fmt.Printf(\"str3: %x\\n\", \"hex this\")\u000A');codeLines.push(' fmt.Printf(\"pointer: %p\\n\", \u0026p)\u000A');codeLines.push(' fmt.Printf(\"width1: |%6d|%6d|\\n\", 12, 345)\u000A');codeLines.push(' fmt.Printf(\"width2: |%6.2f|%6.2f|\\n\", 1.2, 3.45)\u000A');codeLines.push(' fmt.Printf(\"width3: |%-6.2f|%-6.2f|\\n\", 1.2, 3.45)\u000A');codeLines.push(' fmt.Printf(\"width4: |%6s|%6s|\\n\", \"foo\", \"b\")\u000A');codeLines.push(' fmt.Printf(\"width5: |%-6s|%-6s|\\n\", \"foo\", \"b\")\u000A');codeLines.push(' s :\u003D fmt.Sprintf(\"sprintf: a %s\", \"string\")\u000A fmt.Println(s)\u000A');codeLines.push(' fmt.Fprintf(os.Stderr, \"io: an %s\\n\", \"error\")\u000A}\u000A');codeLines.push('');
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