如果您想从一个字符串中提取发生在两个分隔符(不同或相同)之间的所有子字符串，可以使用此函数。它返回一个包含所有子字符串的数组:

function get_substrings_between(str, startDelimiter, endDelimiter) 
{
    var contents = [];
    var startDelimiterLength = startDelimiter.length;
    var endDelimiterLength = endDelimiter.length;
    var startFrom = contentStart = contentEnd = 0;
    
    while(false !== (contentStart = strpos(str, startDelimiter, startFrom))) 
    {
        contentStart += startDelimiterLength;
        contentEnd = strpos(str, endDelimiter, contentStart);
        if(false === contentEnd) 
        {
            break;
        }
        contents.push( str.substr(contentStart, contentEnd - contentStart) );
        startFrom = contentEnd + endDelimiterLength;
    }

    return contents;
}

// https://stackoverflow.com/a/3978237/1066234
function strpos(haystack, needle, offset) 
{
    var i = (haystack+'').indexOf(needle, (offset || 0));
    return i === -1 ? false : i;
}

// Example usage
var string = "We want to extract all infos (essential ones) from within the brackets (this should be fun).";
var extracted = get_substrings_between(string, '(', ')');
console.log(extracted); 
// output: (2) ["essential ones", "this should be fun"]

最初从PHP由raina77ow，移植到Javascript。

下面是一个可重用的函数，它允许你使返回的子字符串包含或排除，然后可选地修剪它:

function get_substring(full_string, substring_1, substring_2, inclusive, trim)
{
    if (full_string === null) { return null; };
    let substring_1_start = full_string.indexOf(substring_1);
    if (substring_1_start === -1 ) { return null; }
    let substring_2_start = full_string.indexOf(substring_2, substring_1_start);
    if (substring_2_start === -1 ) { return null; }
    let substring_1_end = substring_1_start + substring_1.length;
    let substring_2_end = substring_2_start + substring_2.length;
    let return_string = inclusive ? (full_string.substring(substring_1_start, substring_2_end)) : (full_string.substring(substring_1_end, substring_2_start));
    return trim ? return_string.trim() : return_string;
}

使用例子:

//Returns 'cake and ice cream'
get_substring('I like cake and ice cream', 'cake', 'cream', true, true);

//Returns ' and ice '
get_substring('I like cake and ice cream', 'cake', 'cream', false, false);

//Returns 'and ice'
get_substring('I like cake and ice cream', 'cake', 'cream', false, true);

//Returns null
get_substring('I like cake and ice cream', 'cake', 'cookies', false, false);

//Returns null
get_substring('I like cake and ice cream', null, 'cream', false, false);

@Babasaheb Gosavi回答是完美的，如果你有一个子字符串出现(“:”和“;”)。但一旦出现多次，就有点棘手了。

我在多个项目中提出的最佳解决方案是在一个对象中使用四个方法。

第一种方法:实际上是从两个字符串之间获得一个子字符串(但是它只会找到一个结果)。 第二种方法:删除(可能的)最近发现的结果及其前后的子字符串。 第三种方法:将上述两种方法递归地处理一个字符串。 第四种方法:将应用第三种方法并返回结果。

Code

说得够多了，让我们看看代码:

var getFromBetween = {
    results:[],
    string:"",
    getFromBetween:function (sub1,sub2) {
        if(this.string.indexOf(sub1) < 0 || this.string.indexOf(sub2) < 0) return false;
        var SP = this.string.indexOf(sub1)+sub1.length;
        var string1 = this.string.substr(0,SP);
        var string2 = this.string.substr(SP);
        var TP = string1.length + string2.indexOf(sub2);
        return this.string.substring(SP,TP);
    },
    removeFromBetween:function (sub1,sub2) {
        if(this.string.indexOf(sub1) < 0 || this.string.indexOf(sub2) < 0) return false;
        var removal = sub1+this.getFromBetween(sub1,sub2)+sub2;
        this.string = this.string.replace(removal,"");
    },
    getAllResults:function (sub1,sub2) {
        // first check to see if we do have both substrings
        if(this.string.indexOf(sub1) < 0 || this.string.indexOf(sub2) < 0) return;

        // find one result
        var result = this.getFromBetween(sub1,sub2);
        // push it to the results array
        this.results.push(result);
        // remove the most recently found one from the string
        this.removeFromBetween(sub1,sub2);

        // if there's more substrings
        if(this.string.indexOf(sub1) > -1 && this.string.indexOf(sub2) > -1) {
            this.getAllResults(sub1,sub2);
        }
        else return;
    },
    get:function (string,sub1,sub2) {
        this.results = [];
        this.string = string;
        this.getAllResults(sub1,sub2);
        return this.results;
    }
};

如何使用?

例子:

var str = 'this is the haystack {{{0}}} {{{1}}} {{{2}}} {{{3}}} {{{4}}} some text {{{5}}} end of haystack';
var result = getFromBetween.get(str,"{{{","}}}");
console.log(result);
// returns: [0,1,2,3,4,5]

我做的一个小函数，可以抓取之间的字符串，并且可以(可选地)跳过一些匹配的单词来抓取特定的索引。

同样，将start设置为false将使用字符串的开头，将end设置为false将使用字符串的结尾。

将pos1设置为您想要使用的开始文本的位置，1将使用start的第一次出现

Pos2和pos1做同样的事情，但是对于end，并且1将只在start之后使用end的第一次出现，在start之前出现的end将被忽略。

function getStringBetween(str, start=false, end=false, pos1=1, pos2=1){
  var newPos1 = 0;
  var newPos2 = str.length;

  if(start){
    var loops = pos1;
    var i = 0;
    while(loops > 0){
      if(i > str.length){
        break;
      }else if(str[i] == start[0]){
        var found = 0;
        for(var p = 0; p < start.length; p++){
          if(str[i+p] == start[p]){
            found++;
          }
        }
        if(found >= start.length){
          newPos1 = i + start.length;
          loops--;
        }
      }
      i++;
    }
  }

  if(end){
    var loops = pos2;
    var i = newPos1;
    while(loops > 0){
      if(i > str.length){
        break;
      }else if(str[i] == end[0]){
        var found = 0;
        for(var p = 0; p < end.length; p++){
          if(str[i+p] == end[p]){
            found++;
          }
        }
        if(found >= end.length){
          newPos2 = i;
          loops--;
        }
      }
      i++;
    }
  }

  var result = '';
  for(var i = newPos1; i < newPos2; i++){
    result += str[i];
  }
  return result;
}

这是我刚做的东西。

注意，如果在启动后没有找到end，函数将返回启动后的所有内容。它还期望只有一次出现的开始和结束，如果有多次，它将只考虑第一次。

许可:公共领域

/**
 * Extracts a string from `source` that is placed between `start` and `end`. The function
 * considers only one instance of start and before, or the first instance and does not support
 * multiple occurences otherwise. If end string is not found, it will return everything after
 * `start` to the end of the string.
 */
export function stringBetween(source, start, end) {
  if (source.indexOf(start) === -1) {
    return null;
  }

  const sourceSplitByStartString = source.split(start);

  // Note: If start string is the very first occurence in source string, the result will be an
  // array where the first item is an empty string and the next item is of interest.

  if (
    sourceSplitByStartString.length === 1
    || sourceSplitByStartString[1] === ''
  ) {
    // It means that start is either the entire string or is at the very end of the string, so there
    // is not anything between
    return '';
  }

  const afterStart = sourceSplitByStartString[1];

  // If the after separator is not found, return everything after the start separator to the end
  // of the string
  if (afterStart.indexOf(end) === -1) {
    return afterStart;
  }

  const afterStartSplitByEnd = afterStart.split(end);

  if (afterStartSplitByEnd[0] === '') {
    return '';
  }

  return afterStartSplitByEnd[0];
}

测试:

import { stringBetween } from './string';

describe('string utlities', () => {
  describe('stringBetween', () => {
    it('Extracts a substring between 2 other substrings', () => {
      const sample1 = stringBetween('Black cat climbed the tree fast.', 'cat ', ' the tree');
      expect(sample1).toBe('climbed');

      const sample2 = stringBetween('Black cat climbed the tree fast.', 'Black ', ' fast.');
      expect(sample2).toBe('cat climbed the tree');
    });

    it('extracts everything after start if end is not found', () => {
      const sample2 = stringBetween('Black cat climbed the tree fast.', 'Black ', 'not-there');
      expect(sample2).toBe('cat climbed the tree fast.');
    });

    it('returns empty string if start string occurs at the end', () => {
      const sample = stringBetween('Black cat climbed the tree fast.', 'fast.', 'climbed');
      expect(sample).toBe('');
    });

    it('returns empty string if start string is the entire string', () => {
      const sample = stringBetween('Black cat', 'Black cat', 'climbed');
      expect(sample).toBe('');
    });

    it('returns empty string if there is not anything between start and end', () => {
      const sample = stringBetween('Black cat climbed the tree fast.', 'climbed ', 'the tree');
      expect(sample).toBe('');
    });

    it('returns null if start string does not exist in the source string', () => {
      const sample = stringBetween('Black cat climbed the tree fast.', 'not-there ', 'the tree');
      expect(sample).toBe(null);
    });
  });
});

你也可以试试这个:

var str = 'one:two;three';    
str.split(':').pop().split(';')[0]; // returns 'two'