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<html>
<body>
<h1>JavaScript 字符串方法</h1>
<p>charCodeAt() 方法返回字符串中指定位置的字符 unicode 编码：</p>
<p id="demo"></p>
<script>
var str = "HELLO WORLD";
document.getElementById("demo").innerHTML = str.charCodeAt(0);
</script>
</body>
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