jQuery：从具有相同名称的不同选择标记中获取值

Question

I was trying to get the value from different select tag with the same name using jQuery.

The following is the HTML

<div class="row">      
  <div class="col-md-3">
    <h1><i class="fa fa-glass" aria-hidden="true"></i></h1>
    <select class="form-control SelectWine" id="SelectWine" name="SelectWine[]">
      <option value="1">Red</option> <option value="2">Green</option> <option value="3">White</option>                                             </select>
  </div>
  <div class="col-md-3">
    <h1><i class="fa fa-glass" aria-hidden="true"></i></h1>
    <select class="form-control SelectWine" id="SelectWine" name="SelectWine[]">
      <option value="1">Red</option> <option value="2">Green</option> <option value="3">White</option>                                             </select>
  </div>

</div>

The following is how I am accessing in jQuery:

$('.SelectWine').each(function (index){
       var wineId=[];
        wineId.push($(this).val());
        console.log('Wid',wineId[0]);
        console.log('Wid',wineId[1]);
        console.log('Wid',wineId[2]);
   });

I am getting console log as following

Wid 1
Wid undefined
Wid undefined
Wid 3
Wid undefined
Wid undefined

I'm guessing each time it's overriding the value. But i need to store the values from each select tag in to one array.

Note : the first select tag is in the default(index 1) and second one i selected the third option(index 3).

This code is to get the users input for 2 or 3 different products and store it into the cookie for further use, but first i need to store it as array then i am able to store as json array in the cookie.

I tried accessing through the name of the element but it's only responding for accessing using the id.

I was trying for hours, can't figure out a way. your help will be great !!

Answer 1

You need to declare the array outside the loop, otherwise you are creating a new array in each iteration and don't have access to it outside of the each callback due to scope.

var wineId=[];
$('.SelectWine').each(function (index){
       //now each iteration will push to same array
       ....

When you need to generate an array like this you can use map()

var windeId = $('.SelectWine').map(function(){
    return this.value;
}).get();

Answer 2

The main problem is that you are declaring your array inside the for each, so it is getting overwritten. Declare it outside the loop.

Also, unrelated to your problem:

• Your select elements have the same name and id. They can and should share a class name, but not element name and id.
• You can just use 'this.value' rather than '$(this).val()'. Avoiding the unnecessary use of jQuery when possible will improve performance.

https://jsfiddle.net/1ok6ymgf/

var wineId=[];
$('.SelectWine').each(function (index) {      
    wineId.push(this.value);
    console.log('Wid',wineId[0]);
    console.log('Wid',wineId[1]);
    console.log('Wid',wineId[2]);
});

Answer 3

具有不同的ID并使用$('#id_name')调用javascript或具有相同的类名并使用$('.class_name')调用javascript