如何在JavaScript中创建和读取cookie的值?


当前回答

我用js-cookie取得了成功。

<script src="/path/to/js.cookie.js"></script>
<script>
  Cookies.set('foo', 'bar');
  Cookies.get('foo');
</script>

其他回答

我已经使用这个线程的公认答案很多次了。这是一段很棒的代码:简单且可用。但我通常使用babel和ES6和模块,所以如果你像我一样,这里有一些代码可以复制,以更快地使用ES6开发

接受答案改写为模块与ES6:

export const createCookie = ({name, value, days}) => {
  let expires;
  if (days) {
    let date = new Date();
    date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
    expires = '; expires=' + date.toUTCString();
  } else {
    expires = '';
  }
  document.cookie = name + '=' + value + expires + '; path=/';
};

export const getCookie = ({name}) => {
  if (document.cookie.length > 0) {
    let c_start = document.cookie.indexOf(name + '=');
    if (c_start !== -1) {
      c_start = c_start + name.length + 1;
      let c_end = document.cookie.indexOf(';', c_start);
      if (c_end === -1) {
        c_end = document.cookie.length;
      }
      return unescape(document.cookie.substring(c_start, c_end));
    }
  }
  return '';
};

在这之后,你可以简单地导入它作为任何模块(路径当然可能不同):

import {createCookie, getCookie} from './../helpers/Cookie';

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);

下面是前面提到的w3schools的例子。

function setCookie(cname, cvalue, exdays) {
    var d = new Date();
    d.setTime(d.getTime() + (exdays*24*60*60*1000));
    var expires = "expires="+ d.toUTCString();
    document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}

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

以下是可以用于创建和检索cookie的函数。

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

function getCookie(c_name) {
    if (document.cookie.length > 0) {
        c_start = document.cookie.indexOf(c_name + "=");
        if (c_start != -1) {
            c_start = c_start + c_name.length + 1;
            c_end = document.cookie.indexOf(";", c_start);
            if (c_end == -1) {
                c_end = document.cookie.length;
            }
            return unescape(document.cookie.substring(c_start, c_end));
        }
    }
    return "";
}

这是一个代码获取,设置和删除Cookie在JavaScript。

function getCookie(name) { name = name + "="; var cookies = document.cookie.split(';'); for(var i = 0; i <cookies.length; i++) { var cookie = cookies[i]; while (cookie.charAt(0)==' ') { cookie = cookie.substring(1); } if (cookie.indexOf(name) == 0) { return cookie.substring(name.length,cookie.length); } } return ""; } function setCookie(name, value, expirydays) { var d = new Date(); d.setTime(d.getTime() + (expirydays*24*60*60*1000)); var expires = "expires="+ d.toUTCString(); document.cookie = name + "=" + value + "; " + expires; } function deleteCookie(name){ setCookie(name,"",-1); }

来源:http://mycodingtricks.com/snippets/javascript/javascript-cookies/