Grab values of an attribute from all elements in jQuery

You can use something like that: https://jsfiddle.net/g903dyp6/

<entries>
  <entry id="1" />
  <entry id="2" />
  <entry id="3" />
  <entry id="4" />
</entries>

let arr = $.map($('entry'), function(el) {
     return $(el).attr('id');
});

There is not a direct function to do that. However, it can be easily accomplished using .map(). E.g.,

let ids = $('entry').map(function() {
    return this.getAttribute('id');
}).get();

let ids = $('entry').map(function() {
    return this.getAttribute('id');
}).get();

console.log(ids);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<entries>
  <entry id="1" />
  <entry id="2" />
  <entry id="3" />
  <entry id="4" />
</entries>