treert.github.io/char_code_tool/index.html at master · treert/treert.github.io · GitHub

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<!DOCTYPE html>
<html lang="zh-CN">
<head>
  <meta charset="utf-8">
  <title>字符编码工具</title>
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="../global.css">
  <style>
    .toolbar {
      display: flex;
      gap: 10px;
      flex-wrap: wrap;
      align-items: center;
      margin-top: 14px;
    }
    .hint {
      font-size: 13px;
      color: var(--text-secondary);
    }
    #msg {
      font-size: 13px;
      color: #d63031;
      margin-top: 10px;
    }
    #msg:empty {
      display: none;
    }
    #output {
      font-family: var(--mono);
      font-size: 13px;
      line-height: 1.7;
      background: var(--bg);
      border: 1px solid var(--border);
      border-radius: 8px;
      padding: 12px 14px;
      white-space: pre-wrap;
      word-break: break-all;
      min-height: 46px;
    }
    .codepoint-table {
      width: 100%;
      border-collapse: collapse;
      font-size: 13px;
    }
    .codepoint-table th,
    .codepoint-table td {
      padding: 8px 10px;
      border-bottom: 1px solid var(--border);
      text-align: left;
    }
    .codepoint-table th {
      font-size: 12px;
      color: var(--text-secondary);
      letter-spacing: .5px;
    }
    .codepoint-table td {
      font-family: var(--mono);
    }
    .codepoint-table tr:last-child td {
      border-bottom: none;
    }
  </style>
</head>
<body>
  <div class="container">
    <a class="back-link" href="../index.html">← 返回首页</a>

    <header class="page-header">
      <h1>字符编码工具</h1>
      <p>字符串与 JS 字符串字面值互转，查看字符码点与 UTF-8 字节</p>
    </header>

    <section class="panel">
      <h2>输入</h2>
      <textarea id="input" class="mono-input" rows="6" placeholder='输入要转换的字符串，或 JS 字符串字面值（如 "你好\n"）'></textarea>
      <div class="toolbar">
        <button class="btn btn-primary" id="btn-encode">编码为 JS 字面值</button>
        <button class="btn btn-ghost" id="btn-decode">从字面值解码</button>
        <button class="btn btn-ghost" id="btn-copy">复制结果</button>
        <span class="hint">Ctrl + Enter 快捷编码</span>
      </div>
      <div id="msg"></div>
    </section>

    <section class="panel">
      <h2>结果</h2>
      <pre id="output"></pre>
    </section>

    <section class="panel" id="codepoint-panel" hidden>
      <h2>码点明细</h2>
      <table class="codepoint-table">
        <thead>
          <tr><th>字符</th><th>Unicode</th><th>UTF-8 字节</th></tr>
        </thead>
        <tbody id="codepoint-body"></tbody>
      </table>
    </section>
  </div>

  <script>
    'use strict';

    const MAX_ROWS = 200;
    const encoder = new TextEncoder();

    const input = document.getElementById('input');
    const output = document.getElementById('output');
    const msg = document.getElementById('msg');
    const codepointPanel = document.getElementById('codepoint-panel');
    const codepointBody = document.getElementById('codepoint-body');
    const btnEncode = document.getElementById('btn-encode');
    const btnDecode = document.getElementById('btn-decode');
    const btnCopy = document.getElementById('btn-copy');

    function hex(b) {
      return b.toString(16).toUpperCase().padStart(2, '0');
    }

    function toJsLiteral(text) {
      let out = '"';
      for (const ch of text) {
        const cp = ch.codePointAt(0);
        if (ch === '"') out += '\\"';
        else if (ch === '\\') out += '\\\\';
        else if (ch === '\n') out += '\\n';
        else if (ch === '\r') out += '\\r';
        else if (ch === '\t') out += '\\t';
        else if (ch === '\b') out += '\\b';
        else if (ch === '\f') out += '\\f';
        else if (ch === '\v') out += '\\v';
        else if (cp < 0x20 || cp === 0x7F) out += '\\x' + hex(cp);
        else if (cp < 0x7F) out += ch;
        else if (cp <= 0xFFFF) out += '\\u' + cp.toString(16).toUpperCase().padStart(4, '0');
        else out += '\\u{' + cp.toString(16).toUpperCase() + '}';
      }
      return out + '"';
    }

    function encode() {
      const text = input.value;
      if (!text) {
        output.textContent = '';
        codepointPanel.hidden = true;
        msg.textContent = '请输入内容';
        return;
      }
      output.textContent = toJsLiteral(text);
      const truncated = renderCodepoints(text);
      msg.textContent = truncated ? `字符较多，码点表仅显示前 ${MAX_ROWS} 个` : '';
    }

    function decode() {
      let text = input.value;
      if (!text) {
        output.textContent = '';
        codepointPanel.hidden = true;
        msg.textContent = '请输入内容';
        return;
      }
      // 整体被引号包裹时视为完整字面值，去掉首尾引号
      if (text.length >= 2) {
        const q = text[0];
        if ((q === '"' || q === "'" || q === '`') && text[text.length - 1] === q) {
          text = text.slice(1, -1);
        }
      }
      let out = '';
      let i = 0;
      let invalidCount = 0;
      let octalCount = 0;
      const simple = { n: '\n', r: '\r', t: '\t', b: '\b', f: '\f', v: '\v' };
      while (i < text.length) {
        if (text[i] !== '\\') {
          let j = text.indexOf('\\', i);
          if (j === -1) j = text.length;
          out += text.slice(i, j);
          i = j;
          continue;
        }
        const rest = text.slice(i);
        const n = text[i + 1];
        if (n === undefined) {
          // 末尾孤立反斜杠按字面保留
          out += '\\';
          invalidCount++;
          i++;
          continue;
        }
        // 行延续：\ 后紧跟换行不产生字符
        if (n === '\n') { i += 2; continue; }
        if (n === '\r') { i += (text[i + 2] === '\n') ? 3 : 2; continue; }
        if (n.codePointAt(0) === 0x2028 || n.codePointAt(0) === 0x2029) { i += 2; continue; }
        if (Object.hasOwn(simple, n)) { out += simple[n]; i += 2; continue; }
        let m = rest.match(/^\\x([0-9a-fA-F]{2})/);
        if (m) {
          out += String.fromCharCode(parseInt(m[1], 16));
          i += m[0].length;
          continue;
        }
        m = rest.match(/^\\u\{([0-9a-fA-F]+)\}/);
        if (m) {
          const cp = parseInt(m[1], 16);
          if (cp <= 0x10FFFF) {
            out += String.fromCodePoint(cp);
          } else {
            out += m[0];
            invalidCount++;
          }
          i += m[0].length;
          continue;
        }
        m = rest.match(/^\\u([0-9a-fA-F]{4})/);
        if (m) {
          out += String.fromCharCode(parseInt(m[1], 16));
          i += m[0].length;
          continue;
        }
        if (/^\\[xu]/.test(rest)) {
          out += '\\';
          invalidCount++;
          i++;
          continue;
        }
        // \0 之外的八进制转义仅非严格模式有效
        m = rest.match(/^\\([0-3][0-7]{0,2}|[4-7][0-7]?)/);
        if (m) {
          out += String.fromCharCode(parseInt(m[1], 8));
          if (m[1] !== '0') octalCount++;
          i += m[0].length;
          continue;
        }
        // \ 后跟其他字符即该字符本身（如 \\、\"、\a）
        out += n;
        i += 2;
      }
      output.textContent = out;
      const truncated = renderCodepoints(out);
      const notes = [];
      if (invalidCount) notes.push(`${invalidCount} 处无效或超出范围的转义已按字面保留`);
      if (octalCount) notes.push(`${octalCount} 处八进制转义在严格模式下会报错`);
      if (truncated) notes.push(`字符较多，码点表仅显示前 ${MAX_ROWS} 个`);
      msg.textContent = notes.join('；');
    }

    function displayChar(ch) {
      switch (ch) {
        case '\n': return '\\n（换行）';
        case '\r': return '\\r（回车）';
        case '\t': return '\\t（制表）';
        case ' ': return '␣（空格）';
      }
      const cp = ch.codePointAt(0);
      if (cp < 0x20 || cp === 0x7F) return '\\x' + hex(cp);
      return ch;
    }

    function renderCodepoints(text) {
      codepointBody.textContent = '';
      const chars = Array.from(text);
      if (!chars.length) {
        codepointPanel.hidden = true;
        return false;
      }
      codepointPanel.hidden = false;
      for (const ch of chars.slice(0, MAX_ROWS)) {
        const cp = ch.codePointAt(0);
        const tr = document.createElement('tr');

        const tdChar = document.createElement('td');
        tdChar.textContent = displayChar(ch);

        const tdCp = document.createElement('td');
        tdCp.textContent = 'U+' + cp.toString(16).toUpperCase().padStart(4, '0');

        const tdBytes = document.createElement('td');
        tdBytes.textContent = Array.from(encoder.encode(ch), hex).join(' ');

        tr.append(tdChar, tdCp, tdBytes);
        codepointBody.appendChild(tr);
      }
      return chars.length > MAX_ROWS;
    }

    btnEncode.addEventListener('click', encode);
    btnDecode.addEventListener('click', decode);
    btnCopy.addEventListener('click', async () => {
      const text = output.textContent;
      if (!text) {
        msg.textContent = '暂无结果可复制';
        return;
      }
      try {
        await navigator.clipboard.writeText(text);
        btnCopy.textContent = '已复制 ✓';
        setTimeout(() => { btnCopy.textContent = '复制结果'; }, 1500);
      } catch {
        msg.textContent = '复制失败，请手动选择文本复制';
      }
    });
    input.addEventListener('keydown', (e) => {
      if ((e.ctrlKey || e.metaKey) && e.key === 'Enter') {
        e.preventDefault();
        encode();
      }
    });
  </script>
</body>
</html>