var str = <font size='3'>aaaa</font>
请问我怎么把aaa取得呢

// 1
var str = "<font size='3'>aaaa</font>";
var oDiv = document.createElement('div');
oDiv.innerHTML = str;
var sText = oDiv.querySelector('font').textContent;
console.log(sText);
// 2
var s = str.match(/>([^><]+)<\//)[1];
console.log(s);