这个方法开箱即用，效果非常好

function getCookie(cname) {
  var cookies = ` ${document.cookie}`.split(";");
  var val = "";
  for (var i = 0; i < cookies.length; i++) {
    var cookie = cookies[i].split("=");
    if (cookie[0] == ` ${cname}`) {
      return cookie[1];
    }
  }
  return "";
}

function getCookie(name) {
    var pair = document.cookie.split('; ').find(x => x.startsWith(name+'='));
    if (pair)
       return pair.split('=')[1]
}

我写这篇文章是为了在Internet Explorer 11和现代浏览器(如Chromium Edge和Firefox)下工作。

这将获得一个HttpOnly属性为false的cookie值。

    function getCookieValue(keyName) {

        let returnValue = undefined;

        if (keyName && document.cookie) {

            let cookieArray = decodeURIComponent(document.cookie).split('; ');
            for (var i = 0; i < cookieArray.length; i++) {

                if (cookieArray[i]) {
                    let key = cookieArray[i].split('=')[0];
                    if (key && key === keyName) {
                        let value = cookieArray[i].split('=')[1];
                        returnValue = value;
                        break;
                    }
                }

            }

        }

        return returnValue;

    }

我喜欢使用闭包按名称获取cookie值。下面的闭包将允许您通过名称获取cookie值，但只有在更新了cookie字符串时才会解析cookie字符串。

您可以通过以下方法检索cookie的值:

var foo = cookies.get( "bar" );

代码:

var cookies = ( function() {
    var cookieString = null;
    var cookieArray = [];

    function getValOf( name ) {
        if ( newCookies() ) {
            parseCookieString()
        }
        return cookieArray[ name ];
    }

    // Check if new cookies have been added
    function newCookies() {
        return cookieString === document.cookie;
    }

    function parseCookieString() {
        cookieString = document.cookie;

        // Separate cookies
        var cookies = cookieString.split( ";" );

        // Empty previous cookies
        cookieArray = [];

        // Update cookieArray with new name-value pairs
        for ( var i in cookies ) {

            // Separate name and value
            var nameVal = cookies[ i ].split( "=" );
            var name = nameVal[ 0 ].trim();
            var value = nameVal[ 1 ].trim();

            // Add cookie name value pair to dictionary
            cookieArray[ name ] = value;
        }
    }

    return {

        /**
         * Returns value or undefined
         */
        get: function( name ) {
            return getValOf( name );
        }  
    };
})();

我更喜欢在cookie上使用一个正则表达式匹配:

window.getCookie = function(name) {
  var match = document.cookie.match(new RegExp('(^| )' + name + '=([^;]+)'));
  if (match) return match[2];
}

也可以作为函数使用，检查下面的代码。

function check_cookie_name(name) 
    {
      var match = document.cookie.match(new RegExp('(^| )' + name + '=([^;]+)'));
      if (match) {
        console.log(match[2]);
      }
      else{
           console.log('--something went wrong---');
      }
   }

感谢Scott Jungwirth的评论。

获取cookie名称的简单函数:

function getCookie(cn) {
    var name = cn+"=";
    var allCookie = decodeURIComponent(document.cookie).split(';');
    var cval = [];
    for(var i=0; i < allCookie.length; i++) {
        if (allCookie[i].trim().indexOf(name) == 0) {
            cval = allCookie[i].trim().split("=");
        }   
    }
    return (cval.length > 0) ? cval[1] : "";
}