javascript - 多个类上的 querySelectorAll 不起作用

Question

我正在尝试在同一页面上显示多个时钟。但是，querySelectorAll 似乎并没有这样做。我使用的是现代浏览器(已在 Chrome 和 Safari 中测试过)。我做错了什么？

JS代码:

/*global document, window */
function checkTime(i) {
    'use strict';
    if (i < 10) {
        i = "0" + i;
    }
    return i;
}
function a() {
    'use strict';
    var oct = ["0", "1", "2", "3", "4", "5", "6", "7"],
        octtime,
        oct1,
        oct2,
        oct3,
        oct4,
        oct5,
        oct6,
        octvalue,
        point = ".",
        now = new Date(),
        hours = now.getHours(),
        minutes = now.getMinutes(),
        seconds = now.getSeconds(),
        h = checkTime(hours),
        m = checkTime(minutes),
        s = checkTime(seconds),
        totsecs = [hours * 3600 + minutes * 60 + seconds + (now.getTime() % 1000) / 1000];
    octtime = Math.floor(totsecs / (86400 / 262144));
    oct1 = Math.floor(octtime / 32768);
    octtime -= 32768 * oct1;
    oct2 = Math.floor(octtime / 4096);
    octtime -= 4096 * oct2;
    oct3 = Math.floor(octtime / 512);
    octtime -= 512 * oct3;
    oct4 = Math.floor(octtime / 64);
    octtime -= 64 * oct4;
    oct5 = Math.floor(octtime / 8);
    octtime -= 8 * oct5;
    oct6 = octtime;
    octvalue = point + oct[oct1] + oct[oct2] + oct[oct3] + oct[oct4] + oct[oct5] + oct[oct6];
    document.querySelectorAll(".c").innerHTML = h + ":" + m + ":" + s;
    document.querySelectorAll(".d").innerHTML = octvalue;
    window.setTimeout(a);
}
window.onload = a;

HTML代码:

<div class="a">
<table>
<tr>
<td><b>Regular Time</b>
<td><b>Octal Time</b>
<tr>
<td class="c">JS problem
<td class="d">JS problem
</table>
</div>
<br>
<div class="a">
<table>
<tr>
<td><b>Regular Time</b>
<td><b>Octal Time</b>
<tr>
<td class="c">JS problem
<td class="d">JS problem
</table>
</div>
<script src="/1.js"></script>

测试页:http://www.gloryhood.com/ztest.html

Answer 1

是因为querySelectorAll返回 nodeList不是单个节点元素，所以需要迭代设置值

function setHtmlForByClass(clazz, html) {
    var nodes = document.querySelectorAll('.' + clazz)
    for (var i = 0; i < nodes.length; i++) {
        nodes[i].innerHTML = html;
    }
}
setHtmlForByClass('c', h + ":" + m + ":" + s);
setHtmlForByClass('d', octvalue);