给定索引位置，我如何分割该位置所在的句子？

Question

我正在使用JavaScript，我的短信是：

Dana's places, we're having people coming to us people wanna buy condos. They want to move quickly and we're just losing out on a lot of great places. Really what would you say this?

如果我有6的索引位置，我只想得到第一句话：Dana's places, we're having people coming to us people wanna buy condos.

如果我有80的索引位置，我只想得到第二句话：They want to move quickly and we're just losing out on a lot of great places.

如何根据位置来解析句子？

Answer 1

如果我没听错，你应该

分期付款。得到字符串的长度。根据句子长度确定索引指向的位置。

考虑到你需要分开"?，“同样，你只需要遍历这些句子，然后再把它们压平。又分开了。

老实说，使用正则表达式和组可能更干净。

这里是regex版本的

    const paragraph = "Dana's places, we're having people coming to us people wanna buy condos. They want to move quickly and we're just losing out on a lot of great places. Really what would you say this?"


    /**
     * Finds sentence by character index
     * @param index 
     * @param paragraph 
     */
    function findSentenceByCharacterIndex(index, paragraph) {

        const regex = /([^.!?]*[.!?])/gm

        const matches = paragraph.match(regex);

        let cursor = 0;

        let sentenceFound;

        for (const sentence of matches) {

            sentenceFound = sentence;

            cursor += sentence.length;

            if( cursor > index )
            {
                break;
            }
        }

        return sentenceFound;
    }


    const found = findSentenceByCharacterIndex(5, paragraph);

Answer 2

如果你分期付款的话。string对象有一个名为split的原型方法，该方法返回拆分字符串的数组。在下面的示例中，str是一个保存字符串的变量。

const str = 'first sentence. Second sentence. third sentence';
const sentences = str.split('.');
sentences[0] // first sentence
sentences[1] // second sentence, etc

Answer 3

与其尝试使用Array.split，不如对字符串按字符进行一些传统的字符解析。因为我们知道我们要找的是什么索引，所以我们可以简单地看看句子的开头和结尾。

句子是怎么结束的？通常，使用.**，** !**，或** ? -知道这一点，我们可以测试这些字符，并决定字符串的哪一部分，我们应该切分并返回到程序。如果在我们选择的索引之前没有sentence enders(a.e. )。?!.)我们假设字符串的开头是当前语句(0)的开头--我们在所选索引之后也这样做，但如果索引后面没有句柄，则分配str.length。

​

let str = "Dana's places, we're having people coming to us people wanna buy condos. They want to move quickly and we're just losing out on a lot of great places. Really what would you say this?";

let getSentence = (ind, str) => {
  let beg, end, flag, sentenceEnder = ["!", ".", "?"];
  Array.from(str).forEach((c, c_index) => {
  if(c_index < ind && sentenceEnder.includes(c)) {
   beg = c_index + 1;
  }
    if (flag) return;
    if (c_index >= ind && sentenceEnder.includes(c)) {
      end = c_index;
      flag = true;
    }
  });
  end = end || str.length;
  beg = beg || 0;
  return str.slice(beg, end);
}

console.log(getSentence(10, str));
console.log(getSentence(80, str));

​