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
一种可能的解决方案是使用mapper表达式函数。
const regex = /(?:cat|dog|goat)/gmi;
const str = `I have a cat, a dog, and a goat.`;
let mapper = (key) => {
switch (key) {
case "cat":
return "dog"
case "dog":
return "goat";
case "goat":
return "cat"
}
}
let result = str.replace(regex, mapper);
console.log('Substitution result: ', result);
//Substitution result1: I have a dog, a goat, and a cat.
其他回答
<!DOCTYPE html>
<html>
<body>
<p id="demo">Mr Blue
has a blue house and a blue car.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
var str = document.getElementById("demo").innerHTML;
var res = str.replace(/\n| |car/gi, function myFunction(x){
if(x=='\n'){return x='<br>';}
if(x==' '){return x=' ';}
if(x=='car'){return x='BMW'}
else{return x;}//must need
});
document.getElementById("demo").innerHTML = res;
}
</script>
</body>
</html>
我们也可以使用split()和join()方法:
var str = "我有一只猫，一只狗，和一只山羊。"; str = str.split(“猫”)。映射(x =>{返回x.split("dog"))。地图(y = >{返回y.split(“山羊”). join(“猫”);}). join(“山羊”);}). join(“狗”); console.log (str);
使用Array.prototype.reduce ():
更新(更好)答案(使用对象): 此函数将替换所有出现的情况，并且不区分大小写
/**
* Replaces all occurrences of words in a sentence with new words.
* @function
* @param {string} sentence - The sentence to modify.
* @param {Object} wordsToReplace - An object containing words to be replaced as the keys and their replacements as the values.
* @returns {string} - The modified sentence.
*/
function replaceAll(sentence, wordsToReplace) {
return Object.keys(wordsToReplace).reduce(
(f, s, i) =>
`${f}`.replace(new RegExp(s, 'ig'), wordsToReplace[s]),
sentence
)
}
const americanEnglish = 'I popped the trunk of the car in a hurry and in a hurry I popped the trunk of the car'
const wordsToReplace = {
'popped': 'opened',
'trunk': 'boot',
'car': 'vehicle',
'hurry': 'rush'
}
const britishEnglish = replaceAll(americanEnglish, wordsToReplace)
console.log(britishEnglish)
// I opened the boot of the vehicle in a rush and in a rush I opened the boot of the vehicle
原始答案(使用对象数组):
const arrayOfObjects = [
{ plants: 'men' },
{ smart:'dumb' },
{ peace: 'war' }
]
const sentence = 'plants are smart'
arrayOfObjects.reduce(
(f, s) => `${f}`.replace(Object.keys(s)[0], s[Object.keys(s)[0]]), sentence
)
// as a reusable function
const replaceManyStr = (obj, sentence) => obj.reduce((f, s) => `${f}`.replace(Object.keys(s)[0], s[Object.keys(s)[0]]), sentence)
const result = replaceManyStr(arrayOfObjects , sentence1)
Example // ///////////// 1. replacing using reduce and objects // arrayOfObjects.reduce((f, s) => `${f}`.replace(Object.keys(s)[0], s[Object.keys(s)[0]]), sentence) // replaces the key in object with its value if found in the sentence // doesn't break if words aren't found // Example const arrayOfObjects = [ { plants: 'men' }, { smart:'dumb' }, { peace: 'war' } ] const sentence1 = 'plants are smart' const result1 = arrayOfObjects.reduce((f, s) => `${f}`.replace(Object.keys(s)[0], s[Object.keys(s)[0]]), sentence1) console.log(result1) // result1: // men are dumb // Extra: string insertion python style with an array of words and indexes // usage // arrayOfWords.reduce((f, s, i) => `${f}`.replace(`{${i}}`, s), sentence) // where arrayOfWords has words you want to insert in sentence // Example // replaces as many words in the sentence as are defined in the arrayOfWords // use python type {0}, {1} etc notation // five to replace const sentence2 = '{0} is {1} and {2} are {3} every {5}' // but four in array? doesn't break const words2 = ['man','dumb','plants','smart'] // what happens ? const result2 = words2.reduce((f, s, i) => `${f}`.replace(`{${i}}`, s), sentence2) console.log(result2) // result2: // man is dumb and plants are smart every {5} // replaces as many words as are defined in the array // three to replace const sentence3 = '{0} is {1} and {2}' // but five in array const words3 = ['man','dumb','plant','smart'] // what happens ? doesn't break const result3 = words3.reduce((f, s, i) => `${f}`.replace(`{${i}}`, s), sentence3) console.log(result3) // result3: // man is dumb and plants
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"
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.
