chrome团队提出了一种新的方式管理Cookie与Cookie存储API异步(可在谷歌chrome从版本87开始):https://wicg.github.io/cookie-store/

今天已经在其他浏览器中使用了它:https://github.com/mkay581/cookie-store

// load polyfill
import 'cookie-store';

// set a cookie
await cookieStore.set('name', 'value');
// get a cookie
const savedValue = await cookieStore.get('name');

我用这个物体。值是经过编码的，所以在从服务器端读写时必须考虑到这一点。

cookie = (function() {

/**
 * Sets a cookie value. seconds parameter is optional
 */
var set = function(name, value, seconds) {
    var expires = seconds ? '; expires=' + new Date(new Date().getTime() + seconds * 1000).toGMTString() : '';
    document.cookie = name + '=' + encodeURIComponent(value) + expires + '; path=/';
};

var map = function() {
    var map = {};
    var kvs = document.cookie.split('; ');
    for (var i = 0; i < kvs.length; i++) {
        var kv = kvs[i].split('=');
        map[kv[0]] = decodeURIComponent(kv[1]);
    }
    return map;
};

var get = function(name) {
    return map()[name];
};

var remove = function(name) {
    set(name, '', -1);
};

return {
    set: set,
    get: get,
    remove: remove,
    map: map
};

})();

readCookie的改进版本:

function readCookie( name )
{
    var cookieParts = document.cookie.split( ';' )
    ,   i           = 0
    ,   part
    ,   part_data
    ,   value
    ;

    while( part = cookieParts[ i++ ] )
    {
        part_data = part.split( '=' );

        if ( part_data.shift().replace(/\s/, '' ) === name )
        {
            value = part_data.shift();
            break;
        }

    }
    return value;
}

一旦你找到你的cookie值并返回它的值，它就会被打破。在我看来，双劈非常优雅。

if条件上的替换是一个空白修饰，以确保它正确匹配

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)
}

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);

Mozilla创建了一个简单的框架，用于读取和写入cookie，并提供了完整的unicode支持以及如何使用它的示例。

一旦包含在页面中，您可以设置cookie:

docCookies.setItem(name, value);

读饼干:

docCookies.getItem(name);

或者删除cookie:

docCookies.removeItem(name);

例如:

// sets a cookie called 'myCookie' with value 'Chocolate Chip'
docCookies.setItem('myCookie', 'Chocolate Chip');

// reads the value of a cookie called 'myCookie' and assigns to variable
var myCookie = docCookies.getItem('myCookie');

// removes the cookie called 'myCookie'
docCookies.removeItem('myCookie');

查看Mozilla文档中的更多示例和详细信息。饼干页面。

这个简单的js文件的一个版本在github上。