问ajax成功返回<？php<？php作为第一行

EN

<?php<?php<?php<?php

[1] 

<?php<?php<?php<?php
<div class="activity">
<div class="activity-top"></div>
<div class="activity-body"></div>
</div>[1]

function run_loop() {
    $each_item = array();
        if( has_activities( array('current_page' => $_POST['this_page'], 'user_id' => $_POST['user_id'] ) ) ) {

        while ( activity() ) : the_activity();

        $each_item[] =  include( dirname(dirname(__FILE__)).'/activity/activity-entry.php' );

        endwhile;
    }
    exit(json_encode($each_item));

}