li标签是有value属性的，但是限制为数字，并且不赞成使用该属性，可以用data-value来代替
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<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
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<li data-value="1">1</li>
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<script src="//code.jquery.com/jquery-3.3.1.min.js"></script>
<script>
console.log($("li").data("value"))
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