Displaying saved category checked in a plugin?

I solved my own question as follow:

foreach ($categories as $cat)   {
$category_explode = get_the_author_meta( 'Category', $user->ID );
//output 4,5,16 
$cat_ex = explode(',',$category_explode); 
?>
<label> <input type="checkbox" name="category[]" value="<?php echo $cat->cat_ID; ?>" <?php foreach ($cat_ex as $cat_expld)  { if($cat->cat_ID == $cat_expld){echo'checked="checked"';} }?> /><span> <?php echo $cat->cat_name; ?>

  </label>
     <?php  }    ?>