1. Normative
2. Have a dedicated interface dataset

As mentioned above, the access methods of properties are different.

<li data-animal="fish" id="hello">Salmon</li>
<li animal="fish" id="hi">Salmon</li>

var hello = document.getElementById("hello");
var hi = document.getElementById("hi");

// 获取id为hello的元素的data-animal属性
console.log(hello.getAttribute("data-animal")); // "fish"
console.log(hello.dataset.animal); // "fish"

// 获取id为hi的元素的animal属性
console.log(hi.getAttribute("animal")); // "fish"

In the IDE, no warning will be reported if there is a data- prefix.