Question

如何用JS修改整个页面全部的a标签的属性

Answer 1

<a href="1" data-value="no"></a>
<a href="2" data-value="no"></a>

$(function(){

$("a").attr("data-value", "ok");
});

Answer 2

Array.from(document.querySelectorAll('a')).forEach(anchor => anchor.style.color = '#000'());