Do something when a specific element in a loop is clicked in php [duplicate]

As the title says, I want to do something when one of the elements in my loop is clicked. This is my code:

       
<form method="post" action="">
    <div class="table-responsive">
        <table class="table table-hover table-bordered " id="defaultTable" >
            <thead>
            <tr>

                <?php
                $exchangeCol = "";

                <?php foreach ($allColumns as $columnValues): ?>
                <th scope="col">
                    <?php echo $columnValues ?>
                    <button type="submit" name="exchange">

                    <i class="fas fa-exchange-alt" style="float: right; cursor: pointer" id="exch<?php $columnValues ?>"></i>
                    </button>

                </th>

                    <script>
                        $("#<?php echo 'exch' . $columnValues ?>").on('click', function(event) {
                            <?php $exchangeCol = $columnValues ?>
                        });
                    </script>

                <?php endforeach; ?>

                <?php echo $exchangeCol; ?>
            </tr>
            </thead>......

and

<?php if (isset($_POST['exchange'])){
    $table->moveColumn($table->setQueryString('table') , $allColumns[1] , $allColumns[2]);
} ?>

So what I tried is using jquery to pass the value to another variable outside the loop and then use that variable but it doesn't work and I still get all of columns not the column that I click.

How can I print just the column that was clicked?

source https://stackoverflow.com/questions/67892912/do-something-when-a-specific-element-in-a-loop-is-clicked-in-php