A simple related posts function to get posts by categrory in wordpress

relatedPosts.php

<?php
function relatedPosts($mycategory){
	global $post;
  //The post_type can be modified to work with custom post types
	$args = array( 'category' => $mycategory, 'post_type' =>  'post' );
	$postslist = get_posts( $args );
	echo "<h1>Related Posts: </h1>";
	echo "<ul>";
	foreach ($postslist as $key) {
			 if ($key -> post_title != $post -> post_title){
				 $link =  get_permalink($key->ID);
				 $title = $key -> post_title;
				 echo '<h2><li><a href="'.$link.'">'.$title.'</a></li></h2>';
				 echo wp_trim_words( $key->post_content );
				 echo "<br/>";
			 }
	}
	echo "</ul>";
}
?>