Get next & previous post in WordPress

functinos.php

<?php
/**
 * Get Next & Previous post
 *
 * @param $post_id
 * @param $category_id
 * @param string $taxonomy
 *
 * @return array
 */
function get_nextprev_post( $post_id, $category_id, $taxonomy = 'category' ) {
	// Get posts order by post date
	$args = array(
		'post_type'           => 'maddahi',
		'order'               => 'DESC',
		'post_status'         => 'publish',
		'posts_per_page'      => 0,
		'ignore_sticky_posts' => 1,
		'tax_query'           => array(
			array(
				'taxonomy' => $taxonomy,
				'field'    => 'id',
				'terms'    => $category_id,
			)
		),
	);

	$posts = get_posts( $args );

	// get IDs of posts retrieved from get_posts
	$ids = array();
	foreach ( $posts as $post ) {
		$ids[] = $post->ID;
	}

	// get and echo previous and next post in the same category
	$thisindex = array_search( $post_id, $ids );
	$prev_id   = isset( $ids[ $thisindex - 1 ] ) ? $ids[ $thisindex - 1 ] : 0;
	$next_id   = isset( $ids[ $thisindex + 1 ] ) ? $ids[ $thisindex + 1 ] : 0;

	return array( 'next' => $next_id, 'prev' => $prev_id );
}