var arr=['<div','app-header','app-chart','button'];
//下面3种方法均能达到动态生成正则表达式的效果，eval不建议使用
var pattern = /<div(([\s\S])*?)<\/div>/g;
var re =new RegExp(arr[0] + "(([\\s\\S])*?)<\\/div>","g");
var ree = eval("/"+arr[0] + "(([\\s\\S])*?)<\\/div>/g")