替換字符串中與單獨數組中的單詞匹配的單詞

Question

我正在嘗試在字符串中與數組中的一組“過濾器”單詞匹配的任何單詞前添加一個 #。

This is what I have so far
let wordsArray = ['she', 'smile'];
let sentence = 'She has a big smile';
let sentenceArray = sentence.split(" ");
wordsArray.forEach((i, vals) => {
    sentenceArray.forEach((j, sVal) => {
        if (sVal === vals) {
            sentenceArray[j] = `#${j}`;
            console.log(sentenceArray)
        }
    })
});

這是它在控制台中吐出的內容。

app.js:17 (5) ["She", "has", "a", "big", "smile", She: "#She"]
 app.js:17 (5) ["She", "has", "a", "big", "smile", She: "#She", has:
 "#has"] app.js:23 She has a big smile

關於我哪里出錯的任何想法？

Answer 1

forEach回調的第二個參數是index ，您當前正在迭代，而不是值。 您還應該對句子中的單詞調用toLowerCase以與wordsArray中的wordsArray單詞進行wordsArray ：

 let wordsArray = ['she', 'smile']; let sentence = 'She has a big smile'; let sentenceArray = sentence.split(" "); wordsArray.forEach((vals) => { sentenceArray.forEach((sVal, j) => { if (sVal.toLowerCase() === vals) { sentenceArray[j] = `#${sVal}`; } }) }); console.log(sentenceArray)

但是，與嵌套循環相比，構造一組wordsArray計算復雜wordsArray會更低（ O(n)而不是O(n ^ 2) ），而且更加優雅：

 const wordsArray = ['she', 'smile']; const wordsSet = new Set(wordsArray); const sentence = 'She has a big smile'; const result = sentence.split(" ") .map(word => wordsSet.has(word.toLowerCase()) ? '#' + word : word); console.log(result);

Answer 2

復制示例

您可以使用Array.map遍歷句子中的每個單詞，然后如果匹配，則返回帶有#符號的單詞。

let wordsArray = ['she', 'smile'];
let sentence = 'She has a big smile';
let sentenceArray = sentence.split(" ");
sentenceArray = sentenceArray.map((word) => {
  let matchIndex = wordsArray.indexOf(word.toLowerCase())
  return (matchIndex !== -1)
    ? '#'.concat(word)
    : word
})

Answer 3

wordsArray.forEach((word) =>sentence = sentence.replace(new RegExp(word,"ig"),"#"+word))

迭代過濾器中的所有單詞，然后使用正則表達式替換句子中的單詞 new RegExp(word, "ig") 第一個參數是要匹配的短語 第二個參數“ig”只是標志，“i”忽略大小寫靈敏度，“g”在全球范圍內搜索。