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

我扩展了一下@本麦考密克斯。他的工作规则字符串,但不如果我转义字符或通配符。我是这么做的

str = "[curl] 6: blah blah 234433 blah blah";
mapObj = {'\\[curl] *': '', '\\d: *': ''};


function replaceAll (str, mapObj) {

    var arr = Object.keys(mapObj),
        re;

    $.each(arr, function (key, value) {
        re = new RegExp(value, "g");
        str = str.replace(re, function (matched) {
            return mapObj[value];
        });
    });

    return str;

}
replaceAll(str, mapObj)

返回"blah blah 234433 blah blah"

这样它将匹配mapObj中的键,而不是匹配的单词'

其他回答

这招对我很管用:

String.prototype.replaceAll = function(search, replacement) {
    var target = this;
    return target.replace(new RegExp(search, 'g'), replacement);
};

function replaceAll(str, map){
    for(key in map){
        str = str.replaceAll(key, map[key]);
    }
    return str;
}

//testing...
var str = "bat, ball, cat";
var map = {
    'bat' : 'foo',
    'ball' : 'boo',
    'cat' : 'bar'
};
var new = replaceAll(str, map);
//result: "foo, boo, bar"

使用编号的物品,防止再次更换。 如

let str = "I have a %1, a %2, and a %3";
let pets = ["dog","cat", "goat"];

then

str.replace(/%(\d+)/g, (_, n) => pets[+n-1])

它的工作原理:- %\d+查找跟在%后面的数字。括号表示数字。

这个数字(作为字符串)是lambda函数的第二个参数n。

+n-1将字符串转换为数字,然后减去1以索引宠物数组。

然后将%数字替换为数组下标处的字符串。

/g导致lambda函数被重复调用,每个数字被替换为数组中的字符串。

在现代JavaScript中:-

replace_n=(str,...ns)=>str.replace(/%(\d+)/g,(_,n)=>ns[n-1])

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.

具体的解决方案

您可以使用一个函数来替换每一个。

var str = "I have a cat, a dog, and a goat.";
var mapObj = {
   cat:"dog",
   dog:"goat",
   goat:"cat"
};
str = str.replace(/cat|dog|goat/gi, function(matched){
  return mapObj[matched];
});

jsfiddle例子

概括它

如果您想动态地维护正则表达式,并且只是将未来的交换添加到映射中,您可以这样做

new RegExp(Object.keys(mapObj).join("|"),"gi"); 

生成正则表达式。就像这样

var mapObj = {cat:"dog",dog:"goat",goat:"cat"};

var re = new RegExp(Object.keys(mapObj).join("|"),"gi");
str = str.replace(re, function(matched){
  return mapObj[matched];
});

要添加或更改任何替换,您只需编辑地图。

摆弄动态正则表达式

可重复使用

如果你想让它成为一般形式你可以把它变成这样一个函数

function replaceAll(str,mapObj){
    var re = new RegExp(Object.keys(mapObj).join("|"),"gi");

    return str.replace(re, function(matched){
        return mapObj[matched.toLowerCase()];
    });
}

然后你可以把str和你想要的替换的映射传递给函数它会返回转换后的字符串。

摆弄函数

确保对象。key适用于旧的浏览器,添加一个填充,例如从MDN或Es5。

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'