如何在JavaScript中创建和读取cookie的值?
当前回答
我使用以下函数,这些函数是我从各种来源中找到的最好的函数,并剔除了一些错误或差异。
函数setCookie没有高级选项,只有简单的东西,但代码很容易理解,这总是一个优点:
function setCookie(name, value, daysToLive = 3650) { // 10 years default
let cookie = name + "=" + encodeURIComponent(value);
if (typeof daysToLive === "number") {
cookie += "; max-age=" + (daysToLive * 24 * 60 * 60);
document.cookie = cookie + ";path=/";
}
}
function getCookie(name) {
let cookieArr = document.cookie.split(";");
for (let i = 0; i < cookieArr.length; i++) {
let cookiePair = cookieArr[i].split("=");
if (name == cookiePair[0].trim()) {
return decodeURIComponent(cookiePair[1].trim());
}
}
return undefined;
}
function deleteCookie(name) {
setCookie(name, '', -1);
}
其他回答
对于那些需要保存{foo: 'bar'}这样的对象的人,我分享了我编辑过的@KevinBurke的答案。我添加了JSON。stringify和JSON。解析,仅此而已。
cookie = {
set: function (name, value, days) {
if (days) {
var date = new Date();
date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
var expires = "; expires=" + date.toGMTString();
}
else
var expires = "";
document.cookie = name + "=" + JSON.stringify(value) + expires + "; path=/";
},
get : function(name){
var nameEQ = name + "=",
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 JSON.parse(c.substring(nameEQ.length,c.length));
}
return null;
}
}
现在你可以这样做:
cookie.set('cookie_key', {foo: 'bar'}, 30);
cookie.get('cookie_key'); // {foo: 'bar'}
cookie.set('cookie_key', 'baz', 30);
cookie.get('cookie_key'); // 'baz'
简单的阅读
var getCookie = function (name) {
var valueStart = document.cookie.indexOf(name + "=") + name.length + 1;
var valueEnd = document.cookie.indexOf(";", valueStart);
return document.cookie.slice(valueStart, valueEnd)
}
简约且功能齐全的ES6方法:
const setCookie = (name, value, days = 7, path = '/') => {
const expires = new Date(Date.now() + days * 864e5).toUTCString()
document.cookie = name + '=' + encodeURIComponent(value) + '; expires=' + expires + '; path=' + path
}
const getCookie = (name) => {
return document.cookie.split('; ').reduce((r, v) => {
const parts = v.split('=')
return parts[0] === name ? decodeURIComponent(parts[1]) : r
}, '')
}
const deleteCookie = (name, path) => {
setCookie(name, '', -1, path)
}
我写了简单的cookie utils,它有三个功能创建cookie,读取cookie和删除cookie。
var CookieUtils = {
createCookie: function (name, value, expireTime) {
expireTime = !!expireTime ? expireTime : (15 * 60 * 1000); // Default 15 min
var date = new Date();
date.setTime(date.getTime() + expireTime);
var expires = "; expires=" + date.toGMTString();
document.cookie = name + "=" + value + expires + "; path=/";
},
getCookie: function (name) {
var value = "; " + document.cookie;
var parts = value.split("; " + name + "=");
if (parts.length == 2) {
return parts.pop().split(";").shift();
}
},
deleteCookie: function(name) {
document.cookie = name +'=; Path=/; Expires=Thu, 01 Jan 1970 00:00:01 GMT;';
}
};
ES7,使用正则表达式的get()。基于MDN
const Cookie = {
get: name => {
let c = document.cookie.match(`(?:(?:^|.*; *)${name} *= *([^;]*).*$)|^.*$`)[1]
if (c) return decodeURIComponent(c)
},
set: (name, value, opts = {}) => {
/*If options contains days then we're configuring max-age*/
if (opts.days) {
opts['max-age'] = opts.days * 60 * 60 * 24;
/*Deleting days from options to pass remaining opts to cookie settings*/
delete opts.days
}
/*Configuring options to cookie standard by reducing each property*/
opts = Object.entries(opts).reduce(
(accumulatedStr, [k, v]) => `${accumulatedStr}; ${k}=${v}`, ''
)
/*Finally, creating the key*/
document.cookie = name + '=' + encodeURIComponent(value) + opts
},
delete: (name, opts) => Cookie.set(name, '', {'max-age': -1, ...opts})
// path & domain must match cookie being deleted
}
Cookie.set('user', 'Jim', {path: '/', days: 10})
// Set the path to top level (instead of page) and expiration to 10 days (instead of session)
用法- Cookie。Get (name, value [, options]): Options支持所有标准cookie选项,并增加了“days”:
path: '/' - any absolute path. Default: current document location, domain: 'sub.example.com' - may not start with dot. Default: current host without subdomain. secure: true - Only serve cookie over https. Default: false. days: 2 - days till cookie expires. Default: End of session. Alternative ways of setting expiration: expires: 'Sun, 18 Feb 2018 16:23:42 GMT' - date of expiry as a GMT string. Current date can be gotten with: new Date(Date.now()).toUTCString() 'max-age': 30 - same as days, but in seconds instead of days.
其他答案使用“expires”而不是“max-age”来支持旧的IE版本。这个方法需要ES7,所以IE7已经出来了(这不是什么大问题)。
注意:像“=”和“{:}”这样有趣的字符被支持作为cookie值,regex处理开头和结尾的空白(来自其他库)。 如果您想存储对象,可以在和JSON之前或之后对它们进行编码。stringify和JSON。解析、编辑上面的内容,或者添加另一个方法。例如:
Cookie.getJSON = name => JSON.parse(Cookie.get(name))
Cookie.setJSON = (name, value, opts) => Cookie.set(name, JSON.stringify(value), opts);
推荐文章
- 我如何使用Jest模拟JavaScript的“窗口”对象?
- 我如何等待一个承诺完成之前返回一个函数的变量?
- 在JavaScript中根据键值查找和删除数组中的对象
- 使嵌套JavaScript对象平放/不平放的最快方法
- 如何以及为什么'a'['toUpperCase']()在JavaScript工作?
- 有Grunt生成index.html不同的设置
- 文档之间的区别。addEventListener和window。addEventListener?
- 如何检查动态附加的事件监听器是否存在?
- 如何写setTimeout与参数Coffeescript
- 将JavaScript字符串中的多个空格替换为单个空格
- JavaScript: override alert()
- 重置setTimeout
- 如何确保<select>表单字段被禁用时提交?
- jQuery有不聚焦的方法吗?
- 反应钩子-正确的方式清除超时和间隔