Javascript（jQuery）删除长文本的最后一句话

我正在寻找一个javascript函数，它足够聪明，可以删除一长段文本的最后一句话（实际上是一段）。显示复杂性的一些示例文本：

<p>Blabla, some more text here. Sometimes <span>basic</span> html code is used but that should not make the "selection" of the sentence any harder! I looked up the window and I saw a plane flying over. I asked the first thing that came to mind: "What is it doing up there?" She did not know, "I think we should move past the fence!", she quickly said. He later described it as: "Something insane."</p>

如何做到这一点？什么是正确的算法

---

编辑-长文本指的是我段落中的所有内容，而句子指的是一个实际的句子（不是一行），因此在我的例子中，最后一句是：

他后来将其描述为：“疯狂的东西。”

当那一句被删除时，下一句是

她不知道，“我认为我们应该越过栅栏！”，她很快说：“这是一个很好的例子。为什么不创建一个临时变量，将所有的“！”和“？”转换成“.”，拆分该临时变量，删除最后一句，将该临时数组合并成一个字符串，并计算其长度？然后将原始段落的子字符串增加到该长度，定义规则：
//1.句子以大写字母开头
//2.句子前面不带任何内容或[.！？]，但不带[，：；]
//3.如果格式不正确，句子前面可以加引号，例如[“]”
// 4. 在这种情况下，如果引号后面的单词是名称，则句子可能不正确

还有其他规定吗

确定你的目的：
// 1. 删除最后一句话

假设：
如果您从文本字符串中的最后一个字符开始并向后操作，那么您可以将句子的开头标识为：
1.字符前的文本字符串为[.？！]或
2.字符前的文本字符串为[“”]，前面是大写字母
3.每个[.]前面都有空格
4.我们没有更正html标记
5.这些假设不可靠，需要定期调整

可能的解决办法：
读入您的字符串，并将其拆分为空格字符，以便我们以相反的方式查看字符串块

var characterGroups = $('#this-paragraph').html().split(' ').reverse();

如果您的字符串为：

布拉布拉，这里有更多的文字。有时会使用基本的html代码，但这不应该使句子的“选择”变得更难！我抬头看了看窗户，看到一架飞机飞过。我问第一个想到的问题：“它在上面干什么？”她不知道，“我想我们应该越过栅栏！”她很快说。他后来把它描述为：“某种疯狂的东西。”

注意：将使用jQuery中的.text（）方法删除“”标记和其他标记

每个块后面都有一个空格，所以当我们确定了句子的起始位置（通过数组索引）后，我们就知道了空格有什么索引，我们可以在空格从句子末尾开始占据索引的位置拆分原始字符串

console.log(characterGroups[index]); // He at index=6

给我们自己一个变量来标记我们是否找到了它，并给我们自己一个变量来保存数组元素的索引位置，我们将其标识为保存最后一句的开头：

var found = false;
var index = null;

在数组中循环查找以[.！？]结尾或以“where”结尾的元素，其中前一个元素以大写字母开头

var position     = 1,//skip the first one since we know that's the end anyway
    elements     = characterGroups.length,
    element      = null,
    prevHadUpper = false,
    last         = null;

while(!found && position < elements) {
    element = characterGroups[position].split('');

    if(element.length > 0) {
       last = element[element.length-1];

       // test last character rule
       if(
          last=='.'                      // ends in '.'
          || last=='!'                   // ends in '!'
          || last=='?'                   // ends in '?'
          || (last=='"' && prevHadUpper) // ends in '"' and previous started [A-Z]
       ) {
          found = true;
          index = position-1;
          lookFor = last+' '+characterGroups[position-1];
       } else {
          if(element[0] == element[0].toUpperCase()) {
             prevHadUpper = true;
          } else {
             prevHadUpper = false;
          }
       }
    } else {
       prevHadUpper = false;
    }
    position++;
}

现在，您可以运行以前的字符串：

var trimPosition = originalString.lastIndexOf(lookFor)+1;
var updatedString = originalString.substr(0,trimPosition);
console.log(updatedString);

// Blabla, some more text here. Sometimes <span>basic</span> html code is used but that should not make the "selection" of the sentence any harder! I looked up the window and I saw a plane flying over. I asked the first thing that came to mind: "What is it doing up there?" She did not know, "I think we should move past the fence!", she quickly said.

var trimPosition=originalString.lastIndexOf（lookFor）+1；
var updatedString=originalString.substr（0，trimPosition）；
log（updatedString）；
//布拉布拉，这里有更多的文字。有时会使用基本的html代码，但这不会使句子的“选择”变得更加困难！我抬头看了看窗户，看见一架飞机飞过。我第一个想到的问题是：“它在上面干什么？”她不知道，“我想我们应该越过栅栏！”她很快说。

再次运行它并获取：
布拉布拉，这里有更多的文字。有时会使用基本的html代码，但这不会使句子的“选择”变得更加困难！我抬头看了看窗户，看见一架飞机飞过。我首先想到的问题是：“它在上面干什么？”

再次运行它并获取：
布拉布拉，这里有更多的文字。有时会使用基本的html代码，但这不会使句子的“选择”变得更加困难！我抬头看了看窗户，看见一架飞机飞过

再次运行它并获取：
布拉布拉，这里有更多的文字。有时会使用基本的html代码，但这不会使句子的“选择”变得更加困难

再次运行它并获取：
布拉布拉，这里有更多的文字

再次运行它并获取：
布拉布拉，这里有更多的文字

所以，我认为这符合你想要的

作为一项功能：

function trimSentence(string){
    var found = false;
    var index = null;

    var characterGroups = string.split(' ').reverse();

    var position     = 1,//skip the first one since we know that's the end anyway
        elements     = characterGroups.length,
        element      = null,
        prevHadUpper = false,
        last         = null,
        lookFor      = '';

    while(!found && position < elements) {
        element = characterGroups[position].split('');

        if(element.length > 0) {
           last = element[element.length-1];

           // test last character rule
           if(
              last=='.' ||                // ends in '.'
              last=='!' ||                // ends in '!'
              last=='?' ||                // ends in '?'
              (last=='"' && prevHadUpper) // ends in '"' and previous started [A-Z]
           ) {
              found = true;
              index = position-1;
              lookFor = last+' '+characterGroups[position-1];
           } else {
              if(element[0] == element[0].toUpperCase()) {
                 prevHadUpper = true;
              } else {
                 prevHadUpper = false;
              }
           }
        } else {
           prevHadUpper = false;
        }
        position++;
    }


    var trimPosition = string.lastIndexOf(lookFor)+1;
    return string.substr(0,trimPosition);
}

函数微调语句（字符串）{
var=false；
var指数=零；
var characterGroups=string.split（“”）.reverse（）；
var position=1，//跳过第一个，因为我们知道这就是结束
元素=characterGroups.length，
元素=空，
prevHadUpper=false，
last=null，
查找=“”；
while（！found&&position<元素）{
元素=字符组[位置]。拆分（“”）；
如果（element.length>0）{
last=元素[元素长度-1]；
//测试最后一个字符规则
如果(
last='。| 124;//以'.'结尾
last=='！'|///以'！'结尾
last==“？”|///以“？”结尾
（last=='''&&prevhadhupper）//以'''结束，上一个开始[A-Z]
) {
发现=真；
指数=位置-1；
查找=最后一个+''+字符组[位置-1]；
}否则{
if（元素[0]==元素[0].toUpperCase（））{
prevHadUpper=真；
}否则{
prevhadhupper=false；
}
}
}否则{
prevhadhupper=false；
}
位置++；
}
var trimPosition=string.lastIndexOf（lookFor）+1；
返回字符串.substr（0，trimPosition）；
}

如果需要的话，为它制作一个插件是很简单的，但是要注意这些假设！）

这有用吗

谢谢，
AE
应该这样做

/*
Assumptions:
- Sentence separators are a combination of terminators (.!?) + doublequote (optional) + spaces + capital letter. 
- I haven't preserved tags if it gets down to removing the last sentence. 
*/
function removeLastSentence(text) {

    lastSeparator = Math.max(
        text.lastIndexOf("."), 
        text.lastIndexOf("!"), 
        text.lastIndexOf("?")
    );

    revtext = text.split('').reverse().join('');
    sep = revtext.search(/[A-Z]\s+(\")?[\.\!\?]/); 
    lastTag = text.length-revtext.search(/\/\</) - 2;

    lastPtr = (lastTag > lastSeparator) ? lastTag : text.length;

    if (sep > -1) {
        text1 = revtext.substring(sep+1, revtext.length).trim().split('').reverse().join('');
        text2 = text.substring(lastPtr, text.length).replace(/['"]/g,'').trim();

        sWithoutLastSentence = text1 + text2;
    } else {
        sWithoutLastSentence = '';
    }
    return sWithoutLastSentence;
}

/*
TESTS: 

var text = '<p>Blabla, some more text here. Sometimes <span>basic</span> html code is used but that should not make the "selection" of the text any harder! I looked up the window and I saw a plane flying over. I asked the first thing that came to mind: "What is it doing up there?" She did not know, "I think we should move past the fence!", she quickly said. He later described it as: "Something insane. "</p>';

alert(text + '\n\n' + removeLastSentence(text));
alert(text + '\n\n' + removeLastSentence(removeLastSentence(text)));
alert(text + '\n\n' + removeLastSentence(removeLastSentence(removeLastSentence(text))));
alert(text + '\n\n' + removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(text)))));
alert(text + '\n\n' + removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(text))))));
alert(text + '\n\n' + removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(text)))))));
alert(text + '\n\n' + removeLastSentence('<p>Blabla, some more text here. Sometimes <span>basic</span> html code is used but that should not make the "selection" of the text any harder! I looked up the '));
*/

var trimPosition = originalString.lastIndexOf(lookFor)+1;
var updatedString = originalString.substr(0,trimPosition);
console.log(updatedString);

// Blabla, some more text here. Sometimes <span>basic</span> html code is used but that should not make the "selection" of the sentence any harder! I looked up the window and I saw a plane flying over. I asked the first thing that came to mind: "What is it doing up there?" She did not know, "I think we should move past the fence!", she quickly said.

function trimSentence(string){
    var found = false;
    var index = null;

    var characterGroups = string.split(' ').reverse();

    var position     = 1,//skip the first one since we know that's the end anyway
        elements     = characterGroups.length,
        element      = null,
        prevHadUpper = false,
        last         = null,
        lookFor      = '';

    while(!found && position < elements) {
        element = characterGroups[position].split('');

        if(element.length > 0) {
           last = element[element.length-1];

           // test last character rule
           if(
              last=='.' ||                // ends in '.'
              last=='!' ||                // ends in '!'
              last=='?' ||                // ends in '?'
              (last=='"' && prevHadUpper) // ends in '"' and previous started [A-Z]
           ) {
              found = true;
              index = position-1;
              lookFor = last+' '+characterGroups[position-1];
           } else {
              if(element[0] == element[0].toUpperCase()) {
                 prevHadUpper = true;
              } else {
                 prevHadUpper = false;
              }
           }
        } else {
           prevHadUpper = false;
        }
        position++;
    }


    var trimPosition = string.lastIndexOf(lookFor)+1;
    return string.substr(0,trimPosition);
}

/*
Assumptions:
- Sentence separators are a combination of terminators (.!?) + doublequote (optional) + spaces + capital letter. 
- I haven't preserved tags if it gets down to removing the last sentence. 
*/
function removeLastSentence(text) {

    lastSeparator = Math.max(
        text.lastIndexOf("."), 
        text.lastIndexOf("!"), 
        text.lastIndexOf("?")
    );

    revtext = text.split('').reverse().join('');
    sep = revtext.search(/[A-Z]\s+(\")?[\.\!\?]/); 
    lastTag = text.length-revtext.search(/\/\</) - 2;

    lastPtr = (lastTag > lastSeparator) ? lastTag : text.length;

    if (sep > -1) {
        text1 = revtext.substring(sep+1, revtext.length).trim().split('').reverse().join('');
        text2 = text.substring(lastPtr, text.length).replace(/['"]/g,'').trim();

        sWithoutLastSentence = text1 + text2;
    } else {
        sWithoutLastSentence = '';
    }
    return sWithoutLastSentence;
}

/*
TESTS: 

var text = '<p>Blabla, some more text here. Sometimes <span>basic</span> html code is used but that should not make the "selection" of the text any harder! I looked up the window and I saw a plane flying over. I asked the first thing that came to mind: "What is it doing up there?" She did not know, "I think we should move past the fence!", she quickly said. He later described it as: "Something insane. "</p>';

alert(text + '\n\n' + removeLastSentence(text));
alert(text + '\n\n' + removeLastSentence(removeLastSentence(text)));
alert(text + '\n\n' + removeLastSentence(removeLastSentence(removeLastSentence(text))));
alert(text + '\n\n' + removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(text)))));
alert(text + '\n\n' + removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(text))))));
alert(text + '\n\n' + removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(removeLastSentence(text)))))));
alert(text + '\n\n' + removeLastSentence('<p>Blabla, some more text here. Sometimes <span>basic</span> html code is used but that should not make the "selection" of the text any harder! I looked up the '));
*/