我喜欢这个方法:

var str = 'MyLongString:StringIWant;';
var tmpStr  = str.match(":(.*);");
var newStr = tmpStr[1];
//newStr now contains 'StringIWant'

@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]

这可能是可行的解决方案

var str = 'RACK NO:Stock;PRODUCT TYPE:Stock Sale;PART N0:0035719061;INDEX NO:21A627 042;PART NAME:SPRING;';  
var newstr = str.split(':')[1].split(';')[0]; // return value as 'Stock'

console.log('stringvalue',newstr)

下面的函数获取第一个匹配项

function getStringBetween(x: string, start: string, end: string) {
  const regex = new RegExp(`${start}(.*?)${end}`)

  if (regex.test(x)) {
    return regex.exec(x)![1]
  } else return undefined
}

有测试

test("getStringBetween", () => {
  const result = getStringBetween("<em> Jai Ram</em>", "<em>", "</em>")
  expect(result).toEqual(" Jai Ram")
  const result1 = getStringBetween(
    "hare Jai Ram hare hare hare",
    "hare",
    "hare"
  )
  expect(result1).toEqual(" Jai Ram ")
})

我喜欢这个方法:

var str = 'MyLongString:StringIWant;';
var tmpStr  = str.match(":(.*);");
var newStr = tmpStr[1];
//newStr now contains 'StringIWant'

var s = 'MyLongString:StringIWant;';
/:([^;]+);/.exec(s)[1]; // StringIWant