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
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。
其他回答
以防有人想知道为什么原来海报上的解决方案不管用:
var str = "I have a cat, a dog, and a goat.";
str = str.replace(/cat/gi, "dog");
// now str = "I have a dog, a dog, and a goat."
str = str.replace(/dog/gi, "goat");
// now str = "I have a goat, a goat, and a goat."
str = str.replace(/goat/gi, "cat");
// now str = "I have a cat, a cat, and a cat."
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."
<!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>
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
为此，您可以使用https://www.npmjs.com/package/union-replacer。它基本上是一个字符串。Replace (regexp，…)对等体，它允许在一次传递中发生多次替换，同时保留string.replace(…)的全部功能。
披露:我是作者。开发这个库是为了支持更复杂的用户可配置替换，它解决了所有有问题的事情，比如捕获组、反向引用和回调函数替换。
上面的解决方案对于精确的字符串替换来说已经足够好了。
