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<head>
<meta charset="UTF-8" />
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<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
</head>
<body>
<p>第1个p</p>
<p>第2个p</p>
<p>第3个p</p>
<p>第4个p</p>
<p>第5个p</p>
</body>
<script>
var pArr = document.querySelectorAll("p");
const set = new Set(pArr);
set.forEach(function (elements) {
elements.style.color = "red";
elements.style.backgroundColor = "red";
});
</script>
</html>