js怎么删除cookie

function deleteCookie(name) {
  document.cookie = name + '=; expires=Thu, 01 Jan 1970 00:00:00 UTC; path=/;';
}

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

// 读取cookie
function getCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for (var i = 0; i < ca.length; i++) {
    var c = ca[i];
    while (c.charAt(0) == ' ') c = c.substring(1, c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
  }
  return null;
}

// 删除cookie
function deleteCookie(name) {
  document.cookie = name + '=; expires=Thu, 01 Jan 1970 00:00:00 UTC; path=/;';
}

// 使用示例
setCookie('testCookie', 'Hello World!', 1); // 设置一个有效期为1天的cookie
console.log(getCookie('testCookie')); // 输出: Hello World!
deleteCookie('testCookie'); // 删除cookie
console.log(getCookie('testCookie')); // 输出: null