sorry if the question isn't clear enough but let me explain what is happened to me.

now I have 5 graphs that have been created by Pandas and want to use jquery to affect on grid system in bootstrap. all the divs have the following class "col-md-6" except the last child which has "col-md-12", what I would like to do is: to add "col-md-6" to the last child in case of the length of graphs are even number and remove the "col-md-12" from the last one.

actually, this process is working and the class becomes added to the last child after the document is ready, however, the last graph does apply "col-md-12" and does not apply "col-md-6" even though, it has "col-md-6" but when I do a resize for the page the graph starts to apply "col-md-6" on it.

the question is How can I apply the "col-md-6" dynamically without doing resize for the page?

you can see the behavior before and after resize to understand what I mean exactly:-

before do resize

after doing a resize

The code is like so:-

        ...
        <div class="col-md-6 error-graph">
            {% if regular_group %}
            <div style="">
                <div style="max-width: 100%;max-height: 100%">
                    {{ regular_group|safe }}
                </div>
            </div>
            {% endif %}
        </div>

        <div class="col-md-12 error-graph">
            {% if complex_group %}
            <div style="">
                <div style="max-width: 100%;max-height: 100%">
                    {{ complex_group|safe }}
                </div>
            </div>
            {% endif %}
        </div>

<script>

    function add_class(last_child) {
        let error_graph = $(".error-graph");
        if (error_graph.length % 2 === 0) {
            last_child.removeClass("col-md-12").addClass("col-md-6");
        }
        return last_child;
    }

    function resize_graph() {
        {#$(add_class).width($(this).css("width"));#}
        let func = add_class($(".error-graph:last-child"));
        console.log(func);
        {#$(document).load(func.setWidth = 10);#}
    }

    $(document).ready(function () {
         resize_graph();
    });
</script>