javascript - 按名称获取Cookie(Get cookie by name)

Question

I have a getter to get the value from a cookie.(我有一个吸气剂来从cookie中获取价值。)

Now I have 2 cookies by the name shares= and by the name obligations= .(现在，我有2个Cookie，名称分别为shares=和obligations= 。)

I want to make this getter only to get the values from the obligations cookie.(我只想让这个吸气剂从义务cookie中获取值。)

How do I do this?(我该怎么做呢？)

So the for splits the data into separate values and puts it in an array.(因此， for将数据拆分为单独的值，并将其放入数组中。)

 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]);
    }
 }

  ask by translate from so

Answer 1

One approach, which avoids iterating over an array, would be:(一种避免迭代数组的方法是：)

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

Walkthrough(演练)

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 .(如果令牌中不存在令牌，则按令牌拆分字符串将生成一个具有一个字符串（相同值）的数组，或者如果在string中找到令牌，则将生成具有两个字符串的数组。)

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.(第一个（左）元素是令牌之前的字符串，第二个（右）元素是令牌之后的字符串。)

(NOTE: in case string starts with a token, first element is an empty string)(（注意：如果字符串以令牌开头，则第一个元素为空字符串）)

Considering that cookies are stored as follows:(考虑到cookie的存储方式如下：)

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

in order to retrieve specific cookie value, we just need to get string that is after "; {name}=" and before next ";".(为了检索特定的cookie值，我们只需要获取在“; {name} =”之后和下一个“;”之前的字符串。)

Before we do any processing, we prepend the cookies string with "; ", so that every cookie name, including the first one, is enclosed with "; " and "=":(在进行任何处理之前，我们在cookie字符串前添加“;”，以便每个cookie名称（包括第一个）都用“;”和“ =“括起来：)

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

Now, we can first split by "; {name}=", and if token is found in a cookie string (ie we have two elements), we will end up with second element being a string that begins with our cookie value.(现在，我们首先可以用“; {name} =”进行拆分，如果在cookie字符串中找到了令牌（即，我们有两个元素），我们将以第二个元素作为以cookie值开头的字符串结尾。)

Then we pull that out from an array (ie pop), and repeat the same process, but now with ";"(然后我们将其从数组中取出（即pop），并重复相同的过程，但现在使用“;”) as a token, but this time pulling out the left string (ie shift) to get the actual token value.(作为令牌，但是这次拉出左字符串（即shift）以获取实际令牌值。)