如何匹配包含非单词字符的单词？答案

【问题标题】：How do I match a word that has non-word characters?如何匹配包含非单词字符的单词？
【发布时间】：2012-02-28 22:30:48
【问题描述】：

我正在替换字符串中的单词，并尝试根据 '\b' + myword + '\b' 进行匹配但是，当myword 两端都有非单词字符时，这不起作用。

var myword1 = "testword,";
var myword2 = "(testword";
var testString = "<tag>asdftestword, is a (testwordasdf also (testword </tag> (testword, should be replaced everywhere there is a testword,)";

var rx1 = new RegExp(???(myword1) ,'g');
var rx2 = new RegExp(???(myword2) ,'g');
var result1 = testString.replace(rx1, "replacement");
var result2 = testString.replace(rx2, "replacement");

我希望结果是

result1 == "<tag>asdftestword, is a (testwordasdf also (testword </tag> (replacement should be replaced everywhere there is a replacement)"
result2 == "<tag>asdftestword, is a (testwordasdf also replacement </tag> replacement, should be replaced everywhere there is a testword,)"

【问题讨论】：

无论myword 包含哪些字符，都不能以这种方式创建正则表达式。看看how to pass a variable into an regular expression in javascript。
这适用于所有标点符号，它们是 \b 以外的字符（单词的开头/结尾）。这很正常。
@FelixKling 感谢您的提示。 :)

标签： javascript regex

【解决方案1】：

testString.replace( new RegExp('\\b'+myword+'\\b','g'), "replacement");

但是，如果myword 可能包含正则表达式中的特殊字符（例如括号、句点、方括号等），那么您需要escape them first：

RegExp.escape = function(text) {
  if (!RegExp.sRE) {
    var chars = '/.*+?|()[]{}\\'.split('');
    RegExp.sRE = new RegExp('\\'+chars.join('|\\'), 'g');
  }
  return text.replace(RegExp.sRE, '\\$&');
}

var re = new RegExp('\\b'+RegExp.escape(myword)+'\\b','g');

【讨论】：

【解决方案2】：

您不需要正则表达式。只需使用普通字符串替换：

var myword = "testword,";
var testString = "<tag>asdftestword, is a testword</tag> (testword, should be replaced everywhere there is a testword,)";

var result = testString.replace( myword , "replacement");

【讨论】：

我需要它忽略 <tag>asdftestword, jsfiddle.net/g4f8s yeilds <tag>asdfreplacement is a testword</tag> (testword, should be replaced everywhere there is a testword,)
JavaScript 的String.prototype.replace 只替换第一次出现；您必须使用带有 /g 标志的正则表达式来替换所有匹配项。（或者使用其他愚蠢的循环结构。）
用正则表达式全局标志修复var result = testString.replace( /testword,/g , "replacement");

【解决方案3】：

var rx = new RegExp('\\b' + myword ,'g');
var result = testString.replace(rx, 'replacement');

【讨论】：

【解决方案4】：

好的，我终于想通了。看起来它太复杂了，只需要一个 RegExp 我需要多个！

在行动中看到它Here

function EscapeRegex(text) {
    if (!RegExp.sRE) {
    var chars = '/.*+?|()[]{}\\'.split('');
    RegExp.sRE = new RegExp('\\'+chars.join('|\\'), 'g');
    }
    return text.replace(RegExp.sRE, '\\$&');
}

function ReplaceWholeWord(subjectString, wordtofind, replacement){
    var escapedWord = EscapeRegex(wordtofind);
    //simplest scenaro, word to find has non-word characters at begining and end - do basic replace
    if(regexIndexOf(escapedWord, '[^\\w]', 0) == 0 && regexLastIndexOf(escapedWord, '[^\\w]', 0) == wordtofind.length - 1){
        subjectString = subjectString.replace(new RegExp(escapedWord, 'g'), replacement);
    }
    //word to find begins with non-wordcharacter
    else if(regexIndexOf(escapedWord, '[^\\w]', 0) == 0){
        var index = regexIndexOf(subjectString, escapedWord+'[^\\w]', index);
        while(index > 0){
            subjectString = subjectString.substring(0, index) + replacement + subjectString.substring(index + wordtofind.length);
            index = regexIndexOf(subjectString, escapedWord+'[^\\w]', index);
        }
    }
    //word to find ends with non-wordcharacter
    else if(regexLastIndexOf(escapedWord, '[^\\w]', 0) == wordtofind.length - 1){
        var index = regexIndexOf(subjectString, '[^\\w]'+escapedWord, index);
        while(index > 0){
            subjectString = subjectString.substring(0, index) + replacement + subjectString.substring(index + myword.length + 1);
            index = regexIndexOf(subjectString, escapedWord+'[^\\w]', index);
        }
    }
    //word is normal
    else{
        var index = regexIndexOf(subjectString,'[^\\w]'+escapedWord+'[^\\w]', index);
        while(index >= 0){
            subjectString = subjectString.substring(0, index + 1) + replacement + subjectString.substring(index + wordtofind.length + 1);
            index = regexIndexOf(subjectString,'[^\\w]'+escapedWord+'[^\\w]', index);
        }
    }
    return subjectString;
}

【讨论】：