在字符串NodeJS中拆分和计数单词

Question

如果我有两个类似的字符串

s1 = "This is a foo bar sentence ."
s2 = "This sentence is similar to a foo bar sentence ."

我想把字符串拆分成这种格式

x1 = ["This":1,"is":1,"a":1,"bar":1,"sentence":1,"foo":1]
x2 = ["This":1,"is":1,"a":1,"bar":1,"sentence":2,"similar":1,"to":1,"foo":1]

它将字符串单词拆分并计数，形成一对，其中每个字符串表示一个单词，数字表示该单词在字符串中的计数。

Answer 1

删除标点符号，规范化空白，小写，在空格处拆分，使用循环计数索引对象中的单词出现次数。

function countWords(sentence) {
  var index = {},
      words = sentence
              .replace(/[.,?!;()"'-]/g, " ")
              .replace(/s+/g, " ")
              .toLowerCase()
              .split(" ");
    words.forEach(function (word) {
        if (!(index.hasOwnProperty(word))) {
            index[word] = 0;
        }
        index[word]++;
    });
    return index;
}

或者，在ES6箭头功能样式中：

const countWords = sentence => sentence
  .replace(/[.,?!;()"'-]/g, " ")
  .replace(/s+/g, " ")
  .toLowerCase()
  .split(" ")
  .reduce((index, word) => {
    if (!(index.hasOwnProperty(word))) index[word] = 0;
    index[word]++;
    return index;
  }, {});