获取对象的属性为变量时必须用 object[prop] 形式

<style>
p{200px;line-height:50px;margin:20px;cursor:pointer;background:#000;color:#fff;text-align:center;}
</style>

<p data="a1">1111 onclick</p>
<p data="a2">2222 onclick</p>

<span id="span"></span>

<script type="text/javascript">

var a1={
    aa:'aaa',
    bb:'bbb'
};

var a2={
    aa:123,
    bb:'aaaa'
}

var p = document.getElementsByTagName('p');
var span = document.getElementById('span');
for(var i = 0 ; i<p.length; i++){
    p[i].index = i;
    p[i].onclick = function(){
        var list = this.getAttribute('data');
        console.log(window[list].aa);
        span.innerHTML=`变量属性获取属性值需要用[] a.aa : ${window[list].aa}  and a.bb : ${window[list].bb}`;
    }
}

</script>