cookie具体使用的代码

在JavaScript中，你可以使用`document.cookie` API 来操作cookie。下面是一些基本的cookie操作示例：

// 设置一个新的cookie
setCookie('key', 'value', { expires: 7, path: '/' });

function setCookie(name, value, options = {}) {
  let expires = '';
  if (options.expires) {
    const days = options.expires;
    const date = new Date();
    date.setTime(date.getTime() + days * 24 * 60 * 60 * 1000);
    expires = '; expires=' + date.toUTCString();
  }
  document.cookie = `${name}=${encodeURIComponent(value)}${expires}; ${options.path ? `path=${options.path}` : ''}${options.domain ? `domain=${options.domain}` : ''}${options.secure ? '; secure' : ''}`;
}

// 获取cookie值
function getCookie(name) {
  const nameEQ = `${name}=`;
  const cookies = document.cookie.split(';');
  for (let i = 0; i < cookies.length; i++) {
    let cookie = cookies[i];
    while (cookie.charAt(0) === ' ') {
      cookie = cookie.substring(1);
    }
    if (cookie.indexOf(nameEQ) === 0) {
      return decodeURIComponent(cookie.substring(nameEQ.length));
    }
  }
  return null;
}

// 删除cookie
function deleteCookie(name) {
  setCookie(name, '', { expires: -1 });
}