代码示例:(标识:jsck_win_btoa)
<!DOCTYPE html>
<html>
<body>

<h1>Window 对象</h1>

<h2>btoa() 方法</h2>

<p>btoa() 方法以 base-64 编码字符串。</p>
<p>IE9 及更早版本不支持 btoa() 方法。</p>

<p id="demo"></p>

<script>
let text = "Hello World!";
let encoded = window.btoa(text);

document.getElementById("demo").innerHTML = "原始字符串:" + text + "<br>已编码字符串:" + encoded;
</script>

</body>
</html>
运行结果: