var reg3=/\d(\w)\d;
var reg4=/\d(\w)\d/g;
var ts='$1a2b3c4d5e';
var ret=reg3.exec(ts);
console.log(reg3.lastIndex+'\t'+ret.index+'\t'+ret.tostrong());
返回值"0 1 1a2,2"
"0 1 1a2,2"
var reg3=/\d(\w)\d; 少了一个斜杆 因该为var reg3=/\d(\w)\d/;