按名称获取cookie [英] Get cookie by name

问题描述

我有一个getter从cookie获取值。

现在我有两个名为 shares = 的cookie，名称为 obligations = 。

我想使这个getter只从得到的义务cookie的值。

我该如何做？因此，'for'将数据拆分为单独的值并将其放入数组。

  function getCookie1（）{
 //我必须在这里添加什么才能看到obligations =cookie？ 
 //因为现在它搜索所有的cookie。 
 
 var elements = document.cookie.split（'='）; 
 var obligations = elements [1] .split（'％'）; 
 for（var i = 0; i< obligations.length  -  1; i ++）{
 var tmp = obligations [i] .split（'$'）; 
 addProduct1（tmp [0]，tmp [1]，tmp [2]，tmp [3]）; 
} 
} 
  

解决方案

方法，避免迭代数组，将是：

  function getCookie（name）{
 var value = ;+ document.cookie; 
 var parts = value.split（;+ name +=）; 
 if（parts.length == 2）return parts.pop（）。split（;）。 
} 
  

演练

如果token在一个字符串中不存在，或者是一个有两个字符串的数组，那么在token中找到一个字符串（相同值）的数组时，字符串。

第一个（左侧）元素是标记之前的字符串，第二个（右侧）是标记之后的字符串。 p>

（注意：如果字符串以令牌开头，第一个元素是空字符串）

存储如下：

 {name} = {value}; {name} = {value}; ...
  

为了检索特定的cookie值，我们只需要得到; {name} =和下一个;之前。在我们进行任何处理之前，我们在Cookie字符串前加上;，以便每个Cookie名称（包括第一个）都用;和=括起来：

 ; {name} = {value}; {name} = {value}; ...
  

现在，我们可以先用; {name} =分割，如果在cookie字符串中找到token（即我们有两个元素）第二个元素是以我们的cookie值开头的字符串。然后我们从数组（即pop）中拉出，并重复相同的过程，但现在使用;作为令牌，但这次拉出左字符串（即shift）以获取实际令牌值。

I have a getter to get the value from a cookie.

Now I have 2 cookies by the name shares= and by the name obligations= .

I want to make this getter only to get the values from the obligations cookie.

How do I do this? So the 'for' splits the data into separate values and puts it in an array.

 function getCookie1() {
// What do I have to add here to look only in the "obligations=" cookie? 
// Because now it searches all the cookies.

    var elements = document.cookie.split('=');
    var obligations= elements[1].split('%');
    for (var i = 0; i < obligations.length - 1; i++) {
        var tmp = obligations[i].split('$');
        addProduct1(tmp[0], tmp[1], tmp[2], tmp[3]);
    }
 }

解决方案

One approach, which avoids iterating over an array, would be:

function getCookie(name) {
  var value = "; " + document.cookie;
  var parts = value.split("; " + name + "=");
  if (parts.length == 2) return parts.pop().split(";").shift();
}

Walkthrough

Splitting a string by token will produce either, an array with one string (same value), in case token does not exist in a string, or an array with two strings , in case token is found in a string .

The first (left) element is string of what was before the token, and the second one (right) is what is string of what was after the token.

(NOTE: in case string starts with a token, first element is an empty string)

Considering that cookies are stored as follows:

"{name}={value}; {name}={value}; ..."

in order to retrieve specific cookie value, we just need to get string that is after "; {name}=" and before next ";". Before we do any processing, we prepend the cookies string with "; ", so that every cookie name, including the first one, is enclosed with "; " and "=":

"; {name}={value}; {name}={value}; ..."

Now, we can first split by "; {name}=", and if token is found in a cookie string (i.e. we have two elements), we will end up with second element being a string that begins with our cookie value. Then we pull that out from an array (i.e. pop), and repeat the same process, but now with ";" as a token, but this time pulling out the left string (i.e. shift) to get the actual token value.

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