Get the attribute value of each element from a jQuery set, into an array

One-liner with ES6 arrow functions, using jQuery .map():

const ids = $('a.someClass').map((i, el) => el.getAttribute('href')).get();

console.log(ids);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<a href="test1" class="someClass">t1</a>
<a href="test2" class="someClass">t2</a>
<a href="test3" class="someClass">t3</a>

Something like

var idArray = $(".someClass").map(function(){
    return this.id
}).get().join(',');

Working demo

Something like this perhaps?

var ids = [];

$('.myClass').each(function () {
  ids.push($(this).attr('id')); // ids.push(this.id) would work as well.
});