如何从字符串中删除重音字符? 特别是在IE6中,我有这样的东西:

accentsTidy = function(s){
    var r=s.toLowerCase();
    r = r.replace(new RegExp(/\s/g),"");
    r = r.replace(new RegExp(/[àáâãäå]/g),"a");
    r = r.replace(new RegExp(/æ/g),"ae");
    r = r.replace(new RegExp(/ç/g),"c");
    r = r.replace(new RegExp(/[èéêë]/g),"e");
    r = r.replace(new RegExp(/[ìíîï]/g),"i");
    r = r.replace(new RegExp(/ñ/g),"n");                
    r = r.replace(new RegExp(/[òóôõö]/g),"o");
    r = r.replace(new RegExp(/œ/g),"oe");
    r = r.replace(new RegExp(/[ùúûü]/g),"u");
    r = r.replace(new RegExp(/[ýÿ]/g),"y");
    r = r.replace(new RegExp(/\W/g),"");
    return r;
};

但是IE6让我很烦,它好像不喜欢我的正则表达式。


当前回答

这里有一个非常简单的解决方案,没有太多的代码,使用一个非常简单的变音符的映射,其中包括一些或全部映射到包含多个字符的ascii等价物,即Æ => AE, ffi => ffi,等等…还包括一些非常基本的功能测试

var diacriticsMap = {
  '\u00C0': 'A',  // À => A
  '\u00C1': 'A',   // Á => A
  '\u00C2': 'A',   // Â => A
  '\u00C3': 'A',   // Ã => A
  '\u00C4': 'A',   // Ä => A
  '\u00C5': 'A',   // Å => A
  '\u00C6': 'AE', // Æ => AE
  '\u00C7': 'C',   // Ç => C
  '\u00C8': 'E',   // È => E
  '\u00C9': 'E',   // É => E
  '\u00CA': 'E',   // Ê => E
  '\u00CB': 'E',   // Ë => E
  '\u00CC': 'I',   // Ì => I
  '\u00CD': 'I',   // Í => I
  '\u00CE': 'I',   // Î => I
  '\u00CF': 'I',   // Ï => I
  '\u0132': 'IJ', // IJ => IJ
  '\u00D0': 'D',   // Ð => D
  '\u00D1': 'N',   // Ñ => N
  '\u00D2': 'O',   // Ò => O
  '\u00D3': 'O',   // Ó => O
  '\u00D4': 'O',   // Ô => O
  '\u00D5': 'O',   // Õ => O
  '\u00D6': 'O',   // Ö => O
  '\u00D8': 'O',   // Ø => O
  '\u0152': 'OE', // Œ => OE
  '\u00DE': 'TH', // Þ => TH
  '\u00D9': 'U',   // Ù => U
  '\u00DA': 'U',   // Ú => U
  '\u00DB': 'U',   // Û => U
  '\u00DC': 'U',   // Ü => U
  '\u00DD': 'Y',   // Ý => Y
  '\u0178': 'Y',   // Ÿ => Y
  '\u00E0': 'a',   // à => a
  '\u00E1': 'a',   // á => a
  '\u00E2': 'a',   // â => a
  '\u00E3': 'a',   // ã => a
  '\u00E4': 'a',   // ä => a
  '\u00E5': 'a',   // å => a
  '\u00E6': 'ae', // æ => ae
  '\u00E7': 'c',   // ç => c
  '\u00E8': 'e',   // è => e
  '\u00E9': 'e',   // é => e
  '\u00EA': 'e',   // ê => e
  '\u00EB': 'e',   // ë => e
  '\u00EC': 'i',   // ì => i
  '\u00ED': 'i',   // í => i
  '\u00EE': 'i',   // î => i
  '\u00EF': 'i',   // ï => i
  '\u0133': 'ij', // ij => ij
  '\u00F0': 'd',   // ð => d
  '\u00F1': 'n',   // ñ => n
  '\u00F2': 'o',   // ò => o
  '\u00F3': 'o',   // ó => o
  '\u00F4': 'o',   // ô => o
  '\u00F5': 'o',   // õ => o
  '\u00F6': 'o',   // ö => o
  '\u00F8': 'o',   // ø => o
  '\u0153': 'oe', // œ => oe
  '\u00DF': 'ss', // ß => ss
  '\u00FE': 'th', // þ => th
  '\u00F9': 'u',   // ù => u
  '\u00FA': 'u',   // ú => u
  '\u00FB': 'u',   // û => u
  '\u00FC': 'u',   // ü => u
  '\u00FD': 'y',   // ý => y
  '\u00FF': 'y',   // ÿ => y
  '\uFB00': 'ff', // ff => ff
  '\uFB01': 'fi',   // fi => fi
  '\uFB02': 'fl', // fl => fl
  '\uFB03': 'ffi',  // ffi => ffi
  '\uFB04': 'ffl',  // ffl => ffl
  '\uFB05': 'ft', // ſt => ft
  '\uFB06': 'st'  // st => st
};

function replaceDiacritics(str) {
  var returnStr = '';
  if(str) {
    for (var i = 0; i < str.length; i++) {
      if (diacriticsMap[str[i]]) {
        returnStr += diacriticsMap[str[i]];
      } else {
        returnStr += str[i];
      }
    }
  }
  return returnStr;
}

function testStripDiacritics(input, expected) {
  var coChar = replaceDiacritics(input);
  console.log('The character passed in was ' + input);
  console.log('The character that came out was ' + coChar);
  console.log('The character expected was' + expected);
}

testStripDiacritics('À','A');
testStripDiacritics('A','A');
testStripDiacritics('Æ','AE');
testStripDiacritics('AE','AE');
testStripDiacritics('ÇhÀrlËšYŸZŽ','ChArlEsYYZZ');

其他回答

你可以用多种方式创建正则表达式。使用新的regexp -构造函数:

var re = new RegExp("[a-z]", "ig") //(string pattern, string modifiers)

或者使用正则表达式文字表示法:

var re = /[a-z]/ig; // /pattern/modifiers

你把两者混在一起了。

假设你知道你在做什么,我怀疑IE6没有正确地解释文件的编码,因此不能识别文件中的非ascii字符:

确保文件保存为UTF-8格式(例如) 使用Fiddler或其他工具检查web服务器是否发送正确的内容编码HTTP报头。

(虽然它“闻起来”不对,但我会考虑做排序,比如在服务器上使用一些locale感知的东西……但无论如何…)

如果你也对将希腊字符转换为拉丁语感兴趣,我已经包括了希腊字母和一些有向图;它也可以用来表示正字法和音标相结合的希腊式英语。

此外,该版本接受可选选项:

重写对象{replace:string -> search:regex,…} 它覆盖默认替换 忽略Array<string | regex> |字符串 忽略列表项,列表项可以是字符串或正则表达式

const defaultDiacriticsRemovalMap = { '1' : /[\u00B9]/g, '2' : /[\u00B2]/g, '3' : /[\u00B3]/g, 'AU': /\u0391\u03A5|\u0386\u03A5/g, 'EU': /\u0395\u03A5|\u0388\u03A5/g, 'OU': /\u039F\u03A5|\u039F\u038E/g, 'au': /\u03B1\u03C5|\u03AC\u03C5/g, 'eu': /\u03B5\u03C5|\u03AD\u03C5/g, 'ou': /\u03BF\u03C5|\u03BF\u03CD/g, 'Au': /\u0391\u03C5|\u0386\u03C5/g, 'Eu': /\u0395\u03C5|\u0388\u03C5/g, 'Ou': /\u039F\u03C5|\u039F\u03CD/g, 'A' : /[\u0391\u0386\u0041\u24B6\uFF21\u00C0\u00C1\u00C2\u1EA6\u1EA4\u1EAA\u1EA8\u00C3\u0100\u0102\u1EB0\u1EAE\u1EB4\u1EB2\u0226\u01E0\u00C4\u01DE\u1EA2\u00C5\u01FA\u01CD\u0200\u0202\u1EA0\u1EAC\u1EB6\u1E00\u0104\u023A\u2C6F]/g, 'AA': /[\uA732]/g, 'AE': /[\u00C6\u01FC\u01E2]/g, 'AF': /[\u00C6\u01FC\u01E2]/g, 'AO': /[\uA734]/g, 'AU': /[\uA736]/g, 'AV': /[\uA738\uA73A]/g, 'AY': /[\uA73C]/g, 'B' : /[\u0392\u0042\u24B7\uFF22\u1E02\u1E04\u1E06\u0243\u0182\u0181]/g, 'C' : /[\u0043\u24B8\uFF23\u0106\u0108\u010A\u010C\u00C7\u1E08\u0187\u023B\uA73E]/g, 'D' : /[\u00D0\u0394\u0044\u24B9\uFF24\u1E0A\u010E\u1E0C\u1E10\u1E12\u1E0E\u0110\u018B\u018A\u0189\uA779]/g, 'DZ': /[\u01F1\u01C4]/g, 'Dz': /[\u01F2\u01C5]/g, 'E' : /[\u0395\u0388\u0045\u24BA\uFF25\u00C8\u00C9\u00CA\u1EC0\u1EBE\u1EC4\u1EC2\u1EBC\u0112\u1E14\u1E16\u0114\u0116\u00CB\u1EBA\u011A\u0204\u0206\u1EB8\u1EC6\u0228\u1E1C\u0118\u1E18\u1E1A\u0190\u018E]/g, 'F' : /[\u03A6\u0046\u24BB\uFF26\u1E1E\u0191\uA77B]/g, 'G' : /[\u0393\u0047\u24BC\uFF27\u01F4\u011C\u1E20\u011E\u0120\u01E6\u0122\u01E4\u0193\uA7A0\uA77D\uA77E]/g, 'H' : /[\u0397\u0389\u0048\u24BD\uFF28\u0124\u1E22\u1E26\u021E\u1E24\u1E28\u1E2A\u0126\u2C67\u2C75\uA78D]/g, 'I' : /[\u0399\u038A\u03AA\u0049\u24BE\uFF29\u00CC\u00CD\u00CE\u0128\u012A\u012C\u0130\u00CF\u1E2E\u1EC8\u01CF\u0208\u020A\u1ECA\u012E\u1E2C\u0197]/g, 'J' : /[\u004A\u24BF\uFF2A\u0134\u0248]/g, 'K' : /[\u039A\u004B\u24C0\uFF2B\u1E30\u01E8\u1E32\u0136\u1E34\u0198\u2C69\uA740\uA742\uA744\uA7A2]/g, 'KS': /[\u039E]/g, 'L' : /[\u039B\u004C\u24C1\uFF2C\u013F\u0139\u013D\u1E36\u1E38\u013B\u1E3C\u1E3A\u0141\u023D\u2C62\u2C60\uA748\uA746\uA780]/g, 'LJ': /[\u01C7]/g, 'Lj': /[\u01C8]/g, 'M' : /[\u039C\u004D\u24C2\uFF2D\u1E3E\u1E40\u1E42\u2C6E\u019C]/g, 'N' : /[\u039D\u004E\u24C3\uFF2E\u01F8\u0143\u00D1\u1E44\u0147\u1E46\u0145\u1E4A\u1E48\u0220\u019D\uA790\uA7A4]/g, 'NJ': /[\u01CA]/g, 'Nj': /[\u01CB]/g, 'O' : /[\u038C\u039F\u03A9\u038F\u004F\u24C4\uFF2F\u00D2\u00D3\u00D4\u1ED2\u1ED0\u1ED6\u1ED4\u00D5\u1E4C\u022C\u1E4E\u014C\u1E50\u1E52\u014E\u022E\u0230\u00D6\u022A\u1ECE\u0150\u01D1\u020C\u020E\u01A0\u1EDC\u1EDA\u1EE0\u1EDE\u1EE2\u1ECC\u1ED8\u01EA\u01EC\u00D8\u01FE\u0186\u019F\uA74A\uA74C]/g, 'OE': /[\u0152]/g, 'OI': /[\u01A2]/g, 'OO': /[\uA74E]/g, 'OU': /[\u0222]/g, 'P' : /[\u03A0\u0050\u24C5\uFF30\u1E54\u1E56\u01A4\u2C63\uA750\uA752\uA754]/g, 'PS': /[\u03A8]/g, 'Q' : /[\u0051\u24C6\uFF31\uA756\uA758\u024A]/g, 'R' : /[\u03A1\u0052\u24C7\uFF32\u0154\u1E58\u0158\u0210\u0212\u1E5A\u1E5C\u0156\u1E5E\u024C\u2C64\uA75A\uA7A6\uA782]/g, 'S' : /[\u03A3\u0053\u24C8\uFF33\u1E9E\u015A\u1E64\u015C\u1E60\u0160\u1E66\u1E62\u1E68\u0218\u015E\u2C7E\uA7A8\uA784]/g, 'T' : /[\u03A4\u0054\u24C9\uFF34\u1E6A\u0164\u1E6C\u021A\u0162\u1E70\u1E6E\u0166\u01AC\u01AE\u023E\uA786]/g, 'TZ': /[\uA728]/g, 'TH': /[\u0398]/g, 'U' : /[\u0055\u24CA\uFF35\u00D9\u00DA\u00DB\u0168\u1E78\u016A\u1E7A\u016C\u00DC\u01DB\u01D7\u01D5\u01D9\u1EE6\u016E\u0170\u01D3\u0214\u0216\u01AF\u1EEA\u1EE8\u1EEE\u1EEC\u1EF0\u1EE4\u1E72\u0172\u1E76\u1E74\u0244]/g, 'V' : /[\u0056\u24CB\uFF36\u1E7C\u1E7E\u01B2\uA75E\u0245]/g, 'VY': /[\uA760]/g, 'W' : /[\u0057\u24CC\uFF37\u1E80\u1E82\u0174\u1E86\u1E84\u1E88\u2C72]/g, 'X' : /[\u03A7\u0058\u24CD\uFF38\u1E8A\u1E8C]/g, 'Y' : /[\u03A5\u038E\u03AB\u0059\u24CE\uFF39\u1EF2\u00DD\u0176\u1EF8\u0232\u1E8E\u0178\u1EF6\u1EF4\u01B3\u024E\u1EFE]/g, 'Z' : /[\u0396\u005A\u24CF\uFF3A\u0179\u1E90\u017B\u017D\u1E92\u1E94\u01B5\u0224\u2C7F\u2C6B\uA762]/g, 'a' : /[\u03B1\u03AC\u0061\u24D0\uFF41\u1E9A\u00E0\u00E1\u00E2\u1EA7\u1EA5\u1EAB\u1EA9\u00E3\u0101\u0103\u1EB1\u1EAF\u1EB5\u1EB3\u0227\u01E1\u00E4\u01DF\u1EA3\u00E5\u01FB\u01CE\u0201\u0203\u1EA1\u1EAD\u1EB7\u1E01\u0105\u2C65\u0250]/g, 'aa': /[\uA733]/g, 'ae': /[\u00E6\u01FD\u01E3]/g, 'ao': /[\uA735]/g, 'au': /[\uA737]/g, 'av': /[\uA739\uA73B]/g, 'ay': /[\uA73D]/g, 'b' : /[\u03B2\u0062\u24D1\uFF42\u1E03\u1E05\u1E07\u0180\u0183\u0253]/g, 'c' : /[\u00A9\u0063\u24D2\uFF43\u0107\u0109\u010B\u010D\u00E7\u1E09\u0188\u023C\uA73F\u2184]/g, 'd' : /[\u03B4\u0064\u24D3\uFF44\u1E0B\u010F\u1E0D\u1E11\u1E13\u1E0F\u0111\u018C\u0256\u0257\uA77A]/g, 'dz': /[\u01F3\u01C6]/g, 'e' : /[\u20AC\u00F0\u03B5\u03AD\u0065\u24D4\uFF45\u00E8\u00E9\u00EA\u1EC1\u1EBF\u1EC5\u1EC3\u1EBD\u0113\u1E15\u1E17\u0115\u0117\u00EB\u1EBB\u011B\u0205\u0207\u1EB9\u1EC7\u0229\u1E1D\u0119\u1E19\u1E1B\u0247\u025B\u01DD]/g, 'f' : /[\u03C6\u0066\u24D5\uFF46\u1E1F\u0192\uA77C]/g, 'g' : /[\u03B3\u0067\u24D6\uFF47\u01F5\u011D\u1E21\u011F\u0121\u01E7\u0123\u01E5\u0260\uA7A1\u1D79\uA77F]/g, 'h' : /[\u0068\u24D7\uFF48\u0125\u1E23\u1E27\u021F\u1E25\u1E29\u1E2B\u1E96\u0127\u2C68\u2C76\u0265]/g, 'hv': /[\u0195]/g, 'i' : /[\u03B9\u03AF\u03CA\u0390\u03B7\u03AE\u0069\u24D8\uFF49\u00EC\u00ED\u00EE\u0129\u012B\u012D\u00EF\u1E2F\u1EC9\u01D0\u0209\u020B\u1ECB\u012F\u1E2D\u0268\u0131]/g, 'j' : /[\u006A\u24D9\uFF4A\u0135\u01F0\u0249]/g, 'k' : /[\u03BA\u006B\u24DA\uFF4B\u1E31\u01E9\u1E33\u0137\u1E35\u0199\u2C6A\uA741\uA743\uA745\uA7A3]/g, 'ks': /[\u03BE]/g, 'l' : /[\u03BB\u006C\u24DB\uFF4C\u0140\u013A\u013E\u1E37\u1E39\u013C\u1E3D\u1E3B\u017F\u0142\u019A\u026B\u2C61\uA749\uA781\uA747]/g, 'lj': /[\u01C9]/g, 'm' : /[\u03BC\u006D\u24DC\uFF4D\u1E3F\u1E41\u1E43\u0271\u026F]/g, 'n' : /[\u03BD\u006E\u24DD\uFF4E\u01F9\u0144\u00F1\u1E45\u0148\u1E47\u0146\u1E4B\u1E49\u019E\u0272\u0149\uA791\uA7A5]/g, 'nj': /[\u01CC]/g, 'o' : /[\u03C9\u03CE\u03CC\u03BF\u006F\u24DE\uFF4F\u00F2\u00F3\u00F4\u1ED3\u1ED1\u1ED7\u1ED5\u00F5\u1E4D\u022D\u1E4F\u014D\u1E51\u1E53\u014F\u022F\u0231\u00F6\u022B\u1ECF\u0151\u01D2\u020D\u020F\u01A1\u1EDD\u1EDB\u1EE1\u1EDF\u1EE3\u1ECD\u1ED9\u01EB\u01ED\u00F8\u01FF\u0254\uA74B\uA74D\u0275]/g, 'oe': /[\u0153]/g, 'oi': /[\u01A3]/g, 'ou': /[\u0223]/g, 'oo': /[\uA74F]/g, 'p' : /[\u03C0\u0070\u24DF\uFF50\u1E55\u1E57\u01A5\u1D7D\uA751\uA753\uA755]/g, 'ps': /[\u03C8]/g, 'q' : /[\u0071\u24E0\uFF51\u024B\uA757\uA759]/g, 'r' : /[\u00AE\u03C1\u0072\u24E1\uFF52\u0155\u1E59\u0159\u0211\u0213\u1E5B\u1E5D\u0157\u1E5F\u024D\u027D\uA75B\uA7A7\uA783]/g, 's' : /[\u03C2\u03C3\u0073\u24E2\uFF53\u00DF\u015B\u1E65\u015D\u1E61\u0161\u1E67\u1E63\u1E69\u0219\u015F\u023F\uA7A9\uA785\u1E9B]/g, 't' : /[\u03C4\u0074\u24E3\uFF54\u1E6B\u1E97\u0165\u1E6D\u021B\u0163\u1E71\u1E6F\u0167\u01AD\u0288\u2C66\uA787]/g, 'tz': /[\uA729]/g, 'th': /[\u03B8]/g, 'u' : /[\u00B5\u0075\u24E4\uFF55\u00F9\u00FA\u00FB\u0169\u1E79\u016B\u1E7B\u016D\u00FC\u01DC\u01D8\u01D6\u01DA\u1EE7\u016F\u0171\u01D4\u0215\u0217\u01B0\u1EEB\u1EE9\u1EEF\u1EED\u1EF1\u1EE5\u1E73\u0173\u1E77\u1E75\u0289]/g, 'v' : /[\u0076\u24E5\uFF56\u1E7D\u1E7F\u028B\uA75F\u028C]/g, 'vy': /[\uA761]/g, 'w' : /[\u0077\u24E6\uFF57\u1E81\u1E83\u0175\u1E87\u1E85\u1E98\u1E89\u2C73]/g, 'x' : /[\u03C7\u0078\u24E7\uFF58\u1E8B\u1E8D]/g, 'y' : /[\u03C5\u03CD\u03CB\u0079\u24E8\uFF59\u1EF3\u00FD\u0177\u1EF9\u0233\u1E8F\u00FF\u1EF7\u1E99\u1EF5\u01B4\u024F\u1EFF]/g, 'z' : /[\u03B6\u007A\u24E9\uFF5A\u017A\u1E91\u017C\u017E\u1E93\u1E95\u01B6\u0225\u0240\u2C6C\uA763]/g, }; function removeAccent(str, { override, ignore } = {}) { // Function to convert strings to unicode char code escape strings const toHex = s => s.split('').map(c => `\\u${c.charCodeAt().toString(16).padStart(4, "0")}`).join(''); const useToIgnore = ignore && typeof(ignore) === 'string' ? ignore.split('') : ignore; // For every ignore item, replace it with {\uXXXX} so we'll get it back when we finish let useStr = useToIgnore ? useToIgnore.reduce((acc, cur) => acc.replace(cur, m => `{${toHex(m)}}`), str) : str; // Loop through overrides first if (override) { for (const base in override) { useStr = useStr.replace(override[base], base); } } // Loop through the defaults for (const base in defaultDiacriticsRemovalMap) { useStr = useStr.replace(defaultDiacriticsRemovalMap[base], base); } // Restore ignored mappings return useToIgnore ? useStr.replace( /\{?(\\u([0-9a-f]*))\}?/g, (m, g1, hex) => String.fromCharCode(parseInt(hex, 16)) ) : useStr; } // Helper function to convert and print the subjects RegExp.prototype.toJSON = RegExp.prototype.toString; function print([str, options]) { const subjects = document.getElementById('subjects'); const result = document.createElement('div'); result.className = 'result'; if (options) { const opts = document.createElement('div'); opts.textContent = JSON.stringify(options) + "\n"; result.appendChild(opts); } const texts = document.createTextNode(`› ${str}\n‹ ${removeAccent(str, options)}\n`); result.appendChild(texts); subjects.appendChild(result); } // The subjects with some options const subjects = [ ["Mon café est plein de caféïne"], ["Τι αξία έχει ο γάμος στην αγάπη μας μπροστά, είναι κι άλλοι παντρεμένοι κι όμως ζούνε χωριστά. - Ζαμπέτας"], ["ÀÁÂÃÄÅàáâãäåÒÓÔÕÕÖØòóôõöøÈÉÊËèéêëðÇçÐÌÍÎÏìíîïÙÚÛÜ ùúûüÑñŠšŸÿýŽž"], ["¹²³áàâãäåaaaÀÁÂÃÄÅAAAÆccç©CCÇÐÐèéêëeeeeeÈÊËEEEEE€g GiìíîïìiiiÌÍÎÏÌIIIlLnnñNNÑòóôõöoooøÒÓÔÕÖOOOØŒr®RšsߊS ùúûüuuuuÙÚÛÜUUUUýÿÝŸžzzŽZZ", { ignore: ['€', 'Ð', 'Æ'] }], [ "Ο λούτσος του Αυγούστου", { ignore: [/\u03BF\u03C5|\u03BF\u03CD/g] }], ["Η χθεσινή της Κυριακής"], ["Η χθεσινή της Κυριακής", { override: { 'H': /[ΗΉ]/g, 'h': /[ηή]/g } }] ]; // Print all subjects subjects.forEach(print); .result { font-family: monospace; white-space: pre-wrap; margin-top: 10px; padding-bottom: 10px; border-bottom: 1px dashed lightgrey; } .result:last-child { border:0; } .result > div { color: blue; margin-bottom: 4px; } <div id="subjects"></div>

我使用GitHub Jakub Dundalek的存储库Latinize.js。

var latinize = require('latinize');
latinize('ỆᶍǍᶆṔƚÉ áéíóúýčďěňřšťžů'); // => 'ExAmPlE aeiouycdenrstzu'

基于Ian Elliott的优秀解决方案的缩短代码:

accentsTidy = function(s){
    var r = s.toLowerCase();
    non_asciis = {'a': '[àáâãäå]', 'ae': 'æ', 'c': 'ç', 'e': '[èéêë]', 'i': '[ìíîï]', 'n': 'ñ', 'o': '[òóôõö]', 'oe': 'œ', 'u': '[ùúûűü]', 'y': '[ýÿ]'};
    for (i in non_asciis) { r = r.replace(new RegExp(non_asciis[i], 'g'), i); }
    return r;
};

编辑:修正的无效代码