issue with in-array

# PHP 5.3+ anonymous function
add_action( 'widgets_init', function() {
    register_widget( 'Sample_Widget_SO_19246434' );
});

class Sample_Widget_SO_19246434 extends WP_Widget 
{
	function __construct() {
    	    	
		parent::__construct(
			'hottopics',
			esc_html__( 'Hot Topics', 'seoleader' ),
			array( 
                'name' => 'Hot Topics',
                'classname' => 'widget-hot-topics', 
                'description' => __( "Just Recommended" ) 
            )
		);
		
		// Register seoleader Widget
		add_action( 'admin_enqueue_scripts', array( $this, 'seoleader_scripts' ));
    }
    public function postsoption($type, $group){

    	$post_exists = post_type_exists( $type );
    	$whdf = array(82,80,1178,1177);
        if ( $post_exists ) {
        	$get_posts = get_posts( array( 
	            'post_type' => $type,
				'posts_status' =>'publish',
				'posts_per_page'=> -1 
	        ));
	        echo '<optgroup label="' . esc_html__( $group, 'seoleader' ) . '">';
	        foreach( $get_posts as $post )
            {
                printf(
                    '<option value="%1$s" %2$s>%3$s</option>',
                    $post->ID,
                    in_array( $post->ID, $whdf) ? 'selected="selected"' : '',
                    $post->post_title
                );
            }
            echo '</optgroup>';
        }
    }
    public function form( $instance ) 
    {
        $select = isset( $instance['select'] ) ? $instance['select'] : '';

        $limon = $select;

        $post_exists = post_type_exists( 'post' );
		$casestudy_exists = post_type_exists( 'case-study' );
		$service_exists = post_type_exists( 'service' );

        echo '<p>';
        echo '<pre>';
        print_r($limon);
        echo '</pre>';

        if( ($post_exists) || ($casestudy_exists) || ($service_exists) )
        {
            printf(
                '<select multiple="multiple" name="%s[]" id="%s" class="widefat seoleader_select2">',
                $this->get_field_name('select'),
                $this->get_field_id('select')
            );
            $post_exists = post_type_exists( 'post' );
	    	$whdf = array(82,80,1178,1177);
	        if ( $post_exists ) {
	        	$get_posts = get_posts( array( 
		            'post_type' => 'post',
					'posts_status' =>'publish',
					'posts_per_page'=> -1 
		        ));
		        echo '<optgroup label="' . esc_html__( 'Post', 'seoleader' ) . '">';
		        foreach( $get_posts as $post )
	            {
	                printf(
	                    '<option value="%1$s" %2$s>%3$s</option>',
	                    $post->ID,
	                    in_array( $post->ID, $limon) ? 'selected="selected"' : '',
	                    $post->post_title
	                );
	            }
	            echo '</optgroup>';
	        }


            echo '</select>';
        }
        echo '</p>'; ?>
        <script type="text/javascript">
        	jQuery(document).ready(function(){
        		jQuery('.seoleader_select2').select2({
        			 width: '100%'
        		});
        	});
        </script>
        <?php
    }

    public function seoleader_scripts(){

        wp_enqueue_script( 
            'seoleader_recommended_select', 
            get_template_directory_uri() . '/assets/js/select2.min.js', 
            array('jquery'), 
            '', 
            true 
        );
        wp_enqueue_style( 
            'seoleader_recommended_select2', 
            get_template_directory_uri() . '/assets/css/select2.min.css'
        );
		
	
	}

    function update( $new_instance, $old_instance ) 
    {
        $instance = $old_instance;
        $instance['select'] = esc_sql( $new_instance['select'] );
        return $instance;
    }

    function widget( $args, $instance ) 
    {
        echo 'Hello world';
    }
}