How to get string value php ??

How to get string value php ??

i'm have a code jquery

<script>
$(document).ready(function(){ 
    $('.div1').slick({
slidesToShow: 5,
  });
});
</script>

and i'm get value php : 
<input style="text-align: center;" id="<?php echo $this->get_field_id("num"); ?>" name="<?php echo $this->get_field_name("num"); ?>" type="text" value="<?php echo absint($instance["num"]); ?>" size='3' />

How to get string  slidesToShow =  $instance["num"]

Thanks