代码示例:(标识:eg_js_string_charcodeat)
<!DOCTYPE html>
<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>
</html>
运行结果: