Jason C Jason C - 8 days ago 3
HTML Question

Getting array of selected checkbox attributes

In the web application I'm currently working on there are a lot of places where I have many HTML checkboxes that I need to turn into a JS array of selected items. For example:

<input type="checkbox" class="example" data-item="3">
<input type="checkbox" class="example" data-item="5">
<input type="checkbox" class="example" data-item="7">
<input type="checkbox" class="example" data-item="11">


Then I have a lot of logic like this to pack the selected values into an array:

var items = [];
$('.example[data-item]:checked').each(function (_, e) {
items.push(Number($(e).data('item')));
});


My question is just this: Is there some nice way to do this in a one-liner (jQuery is allowed if needed), e.g.:

var items = /* magic */;


I realize I could write a function for this, and I will if there is no way to do it clearly otherwise, but I'm looking for some built-in JS magic that can do it all at once.




For completeness here's a snippet:



$('#button').click(function () {
var items = [];
$('.example[data-item]:checked').each(function (_, e) {
items.push(Number($(e).data('item')));
});
alert(JSON.stringify(items));
});

label { display: flex; align-items: center; }
div { display: inline-flex; flex-direction: column; }
button { margin: 1ex; }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
<label><input type="checkbox" class="example" data-item="3"> Item 3</label>
<label><input type="checkbox" class="example" data-item="5"> Item 5</label>
<label><input type="checkbox" class="example" data-item="7"> Item 7</label>
<label><input type="checkbox" class="example" data-item="11"> Item 11</label>
<label><input type="checkbox" class="example" data-item="13"> Item 13</label>
<label><input type="checkbox" class="example" data-item="17"> Item 17</label>
<label><input type="checkbox" class="example" data-item="19"> Item 19</label>
<button id="button">Click Me</button>
</div>




Answer

I don't see anything wrong with your code but another way could be to use map() and return what you need:

$('#button').click(function() {
  var items = $(".example[data-item]:checked").map(function() {
    return $(this).data('item');
  }).get();
  console.log(items);
});
label {
  display: flex;
  align-items: center;
}

div {
  display: inline-flex;
  flex-direction: column;
}

button {
  margin: 1ex;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
  <label><input type="checkbox" class="example" data-item="3"> Item 3</label>
  <label><input type="checkbox" class="example" data-item="5"> Item 5</label>
  <label><input type="checkbox" class="example" data-item="7"> Item 7</label>
  <label><input type="checkbox" class="example" data-item="11"> Item 11</label>
  <label><input type="checkbox" class="example" data-item="13"> Item 13</label>
  <label><input type="checkbox" class="example" data-item="17"> Item 17</label>
  <label><input type="checkbox" class="example" data-item="19"> Item 19</label>
  <button id="button">Click Me</button>
</div>