js怎样获取session

// 读取所有cookie
var cookies = document.cookie.split(';');
for (var i = 0; i < cookies.length; i++) {
    var cookie = cookies[i].trim();
    if (cookie.indexOf("session=") == 0) {
        var sessionValue = cookie.substring("session=".length, cookie.length);
        console.log("Session value:", sessionValue);
        break;
    }
}

// 使用fetch API发送请求
fetch('/getsession')
    .then(response => response.json())
    .then(data => {
        console.log("Session data:", data);
    })
    .catch(error => console.error('Error:', error));

app.get('/getsession', (req, res) => {
    res.json({ session: req.session });
});

<form action="/submit" method="post">
    <input type="hidden" name="session" value="<%= sessionID %>">
    <!-- 其他字段 -->
</form>

var sessionValue = document.querySelector('input[name="session"]').value;
console.log("Session value:", sessionValue);