似乎无法为特定情况生成正则表达式

您可以使用以下代码：

var re = /<reference>gscl'/applications'/('w+)'/containers'/DATA'/congtentInstances'/subscriptions<'/reference>/;
var m = str.match(re);
if (m) console.log(m[1]);

请注意，regexp对象是在斜杠之间声明的（不将模式括在引号之间）。

该模式使用包含ascii数字和字母（以及下划线）的'w字符类。这个类后面跟着量词+，意思是一个或多个。最后，为了隔离所需的子字符串，使用了一个捕获组。

我不是Regex专家，但以下内容似乎适用于此数据集。

//Your data simulated. 
var data = document.getElementById('data').innerHTML; 
var myRegexp = /'/applications'/([0-9a-zA-Z]*)'/containers/g;
//Group iteration from: http://stackoverflow.com/a/432503/402706
var match = myRegexp.exec(data);
while (match != null) {
    //write out each id that was found
    console.log(match[1]);
    // matched text: match[0]
    // match start: match.index
    // capturing group n: match[n]
    match = myRegexp.exec(data);
}

<script type='text' id='data'>
    <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <om2m:discovery xmlns:om2m="http://uri.etsi.org/m2m" xmlns:xmime="http://www.w3.org/2005/05/xmlmime">
        <om2m:matchSize>65</om2m:matchSize>
        <om2m:discoveryURI>
            <reference>gscl</reference>
            <reference>gscl/scls</reference>
            <reference>gscl/scls/subscriptions</reference>
            <reference>gscl/scls/mgmtObjs</reference>
            <reference>gscl/scls/mgmtObjs/subscriptions</reference>
            <reference>gscl/applications</reference>
            <reference>gscl/applications/subscriptions</reference>
            <reference>gscl/applications/mgmtObjs</reference>
            <reference>gscl/applications/mgmtObjs/subscriptions</reference>
            <reference>gscl/accessRights</reference>
            <reference>gscl/accessRights/subscriptions</reference>
            <reference>gscl/groups</reference>
            <reference>gscl/groups/subscriptions</reference>
            <reference>gscl/containers</reference>
            <reference>gscl/containers/subscriptions</reference>
            <reference>gscl/subscriptions</reference>
            <reference>gscl/accessRights/AR_ADMIN</reference>
            <reference>gscl/accessRights/AR_ADMIN/subscriptions</reference>
            <reference>gscl/scls/nscl</reference>
            <reference>gscl/scls/nscl/applications</reference>
            <reference>gscl/scls/nscl/applications/subscriptions</reference>
            <reference>gscl/scls/nscl/applications/mgmtObjs</reference>
            <reference>gscl/scls/nscl/applications/mgmtObjs/subscriptions</reference>
            <reference>gscl/scls/nscl/accessRights</reference>
            <reference>gscl/scls/nscl/accessRights/subscriptions</reference>
            <reference>gscl/scls/nscl/groups</reference>
            <reference>gscl/scls/nscl/groups/subscriptions</reference>
            <reference>gscl/scls/nscl/containers</reference>
            <reference>gscl/scls/nscl/containers/subscriptions</reference>
            <reference>gscl/scls/nscl/subscriptions</reference>
            <reference>gscl/scls/nscl/attachedDevices</reference>
            <reference>gscl/scls/nscl/attachedDevices/subscriptions</reference>
            <reference>gscl/scls/nscl/notificationChannels</reference>
            <reference>gscl/scls/nscl/mgmtObjs</reference>
            <reference>gscl/scls/nscl/mgmtObjs/subscriptions</reference>
            <reference>gscl/scls/nscl/m2mPocs</reference>
            <reference>gscl/applications/98191axla</reference>
            <reference>gscl/applications/98191axla/subscriptions</reference>
            <reference>gscl/applications/98191axla/containers</reference>
            <reference>gscl/applications/98191axla/containers/subscriptions</reference>
            <reference>gscl/applications/98191axla/accessRights</reference>
            <reference>gscl/applications/98191axla/accessRights/subscriptions</reference>
            <reference>gscl/applications/98191axla/groups</reference>
            <reference>gscl/applications/98191axla/groups/subscriptions</reference>
            <reference>gscl/applications/98191axla/notificationChannels</reference>
            <reference>gscl/applications/98191axla/containers/SENSOR </reference>
            <reference>gscl/applications/98191axla/containers/SENSOR/contentInstances</reference>
            <reference>gscl/applications/98191axla/containers/SENSOR/contentInstances/subscriptions</reference>
            <reference>gscl/applications/98191axla/containers/SENSOR/subscriptions</reference>
            <reference>gscl/applications/98191axla/containers/SENSOR/contentInstances/CI_23326802</reference>
            <reference>gscl/applications/98191axla/containers/DATA</reference>
            <reference>gscl/applications/98191axla/containers/DATA/contentInstances</reference>
            <reference>gscl/applications/98191axla/containers/DATA/contentInstances/subscriptions</reference>
            <reference>gscl/applications/98191axla/containers/DATA/subscriptions</reference>
            <reference>gscl/applications/98191axla/containers/DATA/contentInstances/CI_566628946</reference>
            <reference>gscl/applications/98191axla/containers/CONT_81747241</reference>
            <reference>gscl/applications/98191axla/containers/CONT_81747241/contentInstances</reference>
            <reference>gscl/applications/98191axla/containers/CONT_81747241/contentInstances/subscriptions</reference>
            <reference>gscl/applications/98191axla/containers/CONT_81747241/subscriptions</reference>
            <reference>gscl/applications/98191axla/containers/SENSOR/contentInstances/CI_285448423</reference>
            <reference>gscl/applications/98191axla/containers/CONT_360523761</reference>
            <reference>gscl/applications/98191axla/containers/CONT_360523761/contentInstances</reference>
            <reference>gscl/applications/98191axla/containers/CONT_360523761/contentInstances/subscriptions</reference>
            <reference>gscl/applications/98191axla/containers/CONT_360523761/subscriptions</reference>
            <reference>gscl/applications/98191axla/containers/DATA/contentInstances/CI_395775165</reference>
        </om2m:discoveryURI> </om2m:discovery>
</script>

你可以这样做：

var data = '<reference>gscl/applications/98191axla/containers/CONT_81747241</reference>';
console.log(data.match(/'/applications'/([^]+)(?='/containers)/i)[1]);

基本上，括号将捕获/applications/和/containers