我试图用多个其他单词替换字符串中的多个单词。字符串是“我有一只猫,一只狗和一只山羊。”

然而,这并不会产生“我有一只狗、一只山羊和一只猫”,而是产生“我有一只猫、一只猫和一只猫”。是否有可能在JavaScript中同时用多个其他字符串替换多个字符串,以便产生正确的结果?

var str = "I have a cat, a dog, and a goat.";
str = str.replace(/cat/gi, "dog");
str = str.replace(/dog/gi, "goat");
str = str.replace(/goat/gi, "cat");

//this produces "I have a cat, a cat, and a cat"
//but I wanted to produce the string "I have a dog, a goat, and a cat".

当前回答

const str = '感谢为Stack Overflow贡献一个答案!' Const substr = ['for', 'to'] 函数boldString(str, substr) { 让boldStr boldStr = str 字符串的子串。映射(e => { const strRegExp = new RegExp(e, 'g'); boldStr = boldStr。替换(strRegExp ' <强> $ {e} < / >强'); } ) 返回boldStr }

其他回答

    var str = "I have a cat, a dog, and a goat.";

    str = str.replace(/goat/i, "cat");
    // now str = "I have a cat, a dog, and a cat."

    str = str.replace(/dog/i, "goat");
    // now str = "I have a cat, a goat, and a cat."

    str = str.replace(/cat/i, "dog");
    // now str = "I have a dog, a goat, and a cat."

这个解决方案可以只替换整个单词——例如,当搜索“猫”时,“catch”、“ducat”或“locator”将找不到。这可以通过对正则表达式中每个单词前后的单词字符使用负向后查找(?<!\w)和负向前查找(?!\w)来实现:

(?<!\w)(cathy|cat|ducat|locator|catch)(?!\w)

JSFiddle demo: http://jsfiddle.net/mfkv9r8g/1/

在这个实例中,这可能不能满足您的确切需求,但我发现这是一种有用的方法,可以替换字符串中的多个参数,作为通用解决方案。它将替换参数的所有实例,无论它们被引用了多少次:

String.prototype.fmt = function (hash) {
        var string = this, key; for (key in hash) string = string.replace(new RegExp('\\{' + key + '\\}', 'gm'), hash[key]); return string
}

你可以这样调用它:

var person = '{title} {first} {last}'.fmt({ title: 'Agent', first: 'Jack', last: 'Bauer' });
// person = 'Agent Jack Bauer'

注意!

如果您正在使用动态提供的映射,这里的解决方案都不够!

在这种情况下,有两种解决方法:(1)使用分割连接技术,(2)使用正则表达式和特殊字符转义技术。

这是一个分割连接技术,它比另一个快得多(至少快50%):

var str = "I have {abc} a c|at, a d(og, and a g[oat] {1} {7} {11." var mapObj = { 'c|at': "d(og", 'd(og': "g[oat", 'g[oat]': "c|at", }; var entries = Object.entries(mapObj); console.log( entries .reduce( // Replace all the occurrences of the keys in the text into an index placholder using split-join (_str, [key], i) => _str.split(key).join(`{${i}}`), // Manipulate all exisitng index placeholder -like formats, in order to prevent confusion str.replace(/\{(?=\d+\})/g, '{-') ) // Replace all index placeholders to the desired replacement values .replace(/\{(\d+)\}/g, (_,i) => entries[i][1]) // Undo the manipulation of index placeholder -like formats .replace(/\{-(?=\d+\})/g, '{') );

这一个,是Regex特殊字符转义技术,它也有用,但慢得多:

var str = "I have a c|at, a d(og, and a g[oat]." var mapObj = { 'c|at': "d(og", 'd(og': "g[oat", 'g[oat]': "c|at", }; console.log( str.replace( new RegExp( // Convert the object to array of keys Object.keys(mapObj) // Escape any special characters in the search key .map(key => key.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, '\\$&')) // Create the Regex pattern .join('|'), // Additional flags can be used. Like `i` - case-insensitive search 'g' ), // For each key found, replace with the appropriate value match => mapObj[match] ) );

后者的优点是,它也可以用于不区分大小写的搜索。

所有的解决方案都很好,除了应用于闭包的编程语言(如Coda, Excel,电子表格的REGEXREPLACE)。

我下面的两个原始解决方案只使用1个连接和1个正则表达式。

方法#1:查找替换值

其思想是,如果替换值不在字符串中,则附加替换值。然后,使用一个regex,我们执行所有需要的替换:

var str = "我有一只猫,一只狗,和一只山羊。"; STR = (STR +"||||猫,狗,山羊").replace( /猫(? = [\ s \ s] *(狗))|狗(? = [\ s \ s] *(山羊))|山羊(? = [\ s \ s] *(猫 ))|\|\|\|\|.* $ / gi, " $ 1 $ 2 $ 3”); document.body.innerHTML = str;

解释:

cat(?=[\s\S]*(dog)) means that we look for "cat". If it matches, then a forward lookup will capture "dog" as group 1, and "" otherwise. Same for "dog" that would capture "goat" as group 2, and "goat" that would capture "cat" as group 3. We replace with "$1$2$3" (the concatenation of all three groups), which will always be either "dog", "cat" or "goat" for one of the above cases If we manually appended replacements to the string like str+"||||cat,dog,goat", we remove them by also matching \|\|\|\|.*$, in which case the replacement "$1$2$3" will evaluate to "", the empty string.

方法#2:查找替换对

方法#1的一个问题是它一次不能超过9个替换,这是反向传播组的最大数量。 方法#2声明不只是附加替换值,而是直接替换:

var str = "我有一只猫,一只狗,和一只山羊。"; str = (str + " | | | |,猫= >狗,狗= >山羊,山羊= >猫”).replace ( / (\ b \ w + \ b) (? = [\ s \ s] * \ 1 =>([^,]*))|\|\|\|\|.* $ / gi, " $ 2 "); document.body.innerHTML = str;

解释:

(str+"||||,cat=>dog,dog=>goat,goat=>cat") is how we append a replacement map to the end of the string. (\b\w+\b) states to "capture any word", that could be replaced by "(cat|dog|goat) or anything else. (?=[\s\S]*...) is a forward lookup that will typically go to the end of the document until after the replacement map. ,\1=> means "you should find the matched word between a comma and a right arrow" ([^,]*) means "match anything after this arrow until the next comma or the end of the doc" |\|\|\|\|.*$ is how we remove the replacement map.