pfhwyigou/backend/views/frontend/produce.php

<?php
use backend\assets\AppAsset;
AppAsset::addScript($this,Yii::$app->request->baseUrl.'/js/frontend.js')
?>

<div style="width: 500px;height:500px;">
            <div style="margin:0 auto;height:50px;line-height: 50px;margin-left: 50px;">
                    <?php  highlight_string($str) ?>
            </div>
</div>