Here is the working solution
if(have_posts()):
while(have_posts()):the_post();
?>
<article class="post">
<a href="<?php the_permalink(); ?>">
<h2>
<?php the_title(); ?>
</h2>
</a>
<small>
<?php
$categories = get_the_category();
$separator = ", ";
$output = '';
if($categories){
for( $i= 0; $i<count($categories); $i++){
$output .= '<a href="'.get_category_link($categories[$i]->term_id).'">'.$categories[$i]->name.'</a>'.$separator;
}
}
echo trim($output,$separator);
?>
</small>
<p>
<?php the_content(); ?>
</p>
</article>
<?php
endwhile;
else :
echo "No Posts Found";
endif;