用javascript代码更改cookie另一个cookie

function setCookie(name, value, days) {
    let expires = "";
    if (days) {
        const date = new Date();
        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
        expires = "; expires=" + date.toUTCString();
    }
    document.cookie = name + "=" + (value || "") + expires + "; path=/";
}

function deleteCookie(name) {
    document.cookie = name + '=; Max-Age=-99999999;';
}

// 假设我们要更改名为 'oldCookieName' 的cookie
const oldCookieName = 'oldCookieName';
const newCookieValue = 'newValue';
const cookieExpiryDays = 7; // 设置新cookie的有效期为7天

// 删除旧的cookie
deleteCookie(oldCookieName);

// 设置新的cookie
setCookie(oldCookieName, newCookieValue, cookieExpiryDays);