如何将一串句子一分为二,分成两个长度尽可能相似的字符串数组?

首先把每件事都分成几个句子。然后找到最佳位置并再次加入。

var a = "A few sentences. For tests. The point of these sentences is to be used as examples.";
var b = "A couple more sentences. These ones are shorter.";
var c = "Blah. Foo. Bar. Baz. Test. Test 2. Test C.";
var d = "Test sentence.";

String.prototype.halve = function() {
  const ideaLength = this.length / 2;
  const sentences = this.split('.').map(it => it.trim()).filter(it => it != '');
  let current = sentences[0].length + 1;
  let min = Math.abs(current - ideaLength);
  let minPosition = 0;

  for (let i = 1; i < sentences.length; i++) {
    current = current + 2 + sentences[i].length;
    const different = Math.abs(ideaLength - current);
    
    if (different < min) {
      min = different;
      minPosition = i;
    }
  }
  
  const first = sentences.slice(0, minPosition + 1).join('. ') + ".";
  const second = sentences.slice(minPosition + 1).join('. ') + ".";
  
  return [first, second === "." ? "" : second];
}

console.log(a.halve());
console.log(b.halve());
console.log(c.halve());
console.log(d.halve());

Reflect.set(String.prototype, 'halve', function(){
  let mid = Math.floor(this.length/2)
  let i = mid - 1, j = mid, sep = mid
  while(j<this.length) {
    if(this[i]==='.') { sep = i + 1; break }
    if(this[j]==='.') { sep = j + 1; break }
    i--
    j++
  }
  return [this.slice(0,sep), this.slice(sep)]
})

var a = "A few sentences. For tests. The point of these sentences is to be used as examples.";
var b = "A couple more sentences. These ones are shorter.";
var c = "Blah. Foo. Bar. Baz. Test. Test 2. Test C.";
var d = "Test sentence.";

console.log(a.halve()) // ["A few sentences. For tests.", "The point of these sentences is to be used as examples."]
console.log(b.halve()) // ["A couple more sentences.", "These ones are shorter."]
console.log(c.halve()) // ["Blah. Foo. Bar. Baz.", "Test. Test 2. Test C."]
console.log(d.halve()) // ["Test sentence.", ""]

这可以通过找出中间位置来解决 indexOf lastIndexOf :

var a = "A few sentences. For tests. The point of these sentences is to be used as examples.";
var b = "A couple more sentences. These ones are shorter.";
var c = "Blah. Foo. Bar. Baz. Test. Test 2. Test C.";
var d = "Test sentence.";
var e = "A. B. C. D. E. F. G. H. The point of these sentences is to be used as examples."
var f = "The point of these sentences is to be used as examples. A. B. C. D. E. F. G. H."

const half = str => {
  let middle = Math.floor(str.length / 2)
  let nextDot = str.lastIndexOf('.', middle)
  nextDot = nextDot <= 0 ? str.indexOf('.', middle)+1 : nextDot+1
  return [str.substr(0, nextDot), str.substr(nextDot, str.length).trim()]
}

console.log(half(a))
console.log(half(b))
console.log(half(c))
console.log(half(d))
console.log(half(e))
console.log(half(f))

lastIndexOf 索引 为了找出你需要在中间位置朝哪个方向走。一旦你得到了中间,那么它就是在使用 substr 去拿碎片。

下面也完成了工作。它将根据何时有“”将句子拆分为数组。使用这个新数组,您可以使用Math.floor()获得数组的中间部分,并对其进行取整。然后,一些条件将对事情进行排序。

var a = "A few sentences. For tests. The point of these sentences is to be used as examples.";
var b = "A couple more sentences. These ones are shorter.";
var c = "Blah. Foo. Bar. Baz. Test. Test 2. Test C.";
var d = "Test sentence.";

function splitString(str){
    var workSplit = str.split(" ");
    var midPoint = Math.floor(workSplit.length / 2);
    var result = [[],[]];
    for(var char in workSplit){
        if(char < midPoint){
            result[0].push(workSplit[char])
        } else {
            result[1].push(workSplit[char]);
        }
    }
    return [result[0].join(" "), result[1].join(" ")]
}

console.log(splitString(a));
console.log(splitString(b));
console.log(splitString(c));
console.log(splitString(d));

首先,使用此答案查找字符串中出现的所有“.”。

然后,找到最靠近中间的点,并将其拆分(例如,使用此处的答案: split string in two on given index and return both parts )

一些代码:

function splitValue(value, index) {
  return [value.substring(0, index), value.substring(index)];
}

function splitStringInTwo(str) {
  const half = Math.trunc(str.length / 2);
  let slicePoint = {position: -1, distance: 9999};

  if (str.indexOf('.')  === -1) {
    return splitValue(str, str.length / 2);
  }

  for (let i = 1; i > 0; i =  str.indexOf('.', i) + 1) {
    if (Math.abs(i - half) < slicePoint.distance) {
      slicePoint = {position: i, distance: Math.abs(i - half)}; // Distance is shrinking, save it.
    } else {
      return splitValue(str, slicePoint.position); // Distance it growing. Stop.
    }
  }


}

const myString = "Here is a first string. My second, though, is larger by a fair amount of characters. I don't want it to be split.";

console.log(splitStringInTwo(myString));