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

function substringBetween(s, a, b) {
    var p = s.indexOf(a) + a.length;
    return s.substring(p, s.indexOf(b, p));
}

// substringBetween('MyLongString:StringIWant;', ':', ';') -> StringIWant
// substringBetween('MyLongString:StringIWant;;', ':', ';') -> StringIWant
// substringBetween('MyLongString:StringIWant;:StringIDontWant;', ':', ';') -> StringIWant

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

使用分割()

var s = 'MyLongString:StringIWant;';
var arrStr = s.split(/[:;]/);
alert(arrStr);

arrStr将包含所有由:或; 通过for循环访问每个字符串

for(var i=0; i<arrStr.length; i++)
    alert(arrStr[i]);

您可以使用这个函数-

function getStringInBetween(string, start , end) {
    // start and end will be excluded
    var indexOfStart = string.indexOf(start)
    indexOfStart = indexOfStart + start.length;
    var newString = string.slice(indexOfStart)
    var indexOfEnd = newString.indexOf(end)
    return newString.slice(0, indexOfEnd)
}

对于前-

let string = "<div class = 'mice'> I know how to code </div>"
let start = "<div class = 'mice'> "
let end = " </div>"
//then, getStringInBetween(string, start, end) returns "I know how to code"

尝试使用javascript在两个字符之间获取子字符串。

        $("button").click(function(){
            var myStr = "MyLongString:StringIWant;";
            var subStr = myStr.match(":(.*);");
            alert(subStr[1]);
        });

从@ Find子字符串之间的两个字符与jQuery