Im a newb to php and programming in general, so bare with me guys

I have two arrays, one with categories, and the other with articles. If the category array has corresponding articles in the articles array, I want the category name and the corresponding articles to be displayed.

If a category has no articles, then it is not displayed.

Here's an example:
--You have two categories in the category array: news and sports
--You have four articles in the article array, all of which belong to the sports category
--OUPUT: The code only displays the sports category with the sports articles, since there are no news articles

The code I have written thus far displays the category name regardless of whether or not a category has corresponding articles. I'm having trouble writing a method that checks whether a category has articles.

Does anyone know of a way I can compare the two arrays to get the desired output? Any help would be greatly appreciated!

PHP Code:
foreach($categories as $row1)
   {
    
$cat_id $row1['id'];

    
    echo 
'<br>';
    echo 
'<br>';
    echo 
$row1['name'];
    echo 
'<br>';
    
     foreach(
$art_array as $row2)
     {
       
$artcatid $row2['category'];
       
       if (
$cat_id == $artcatid)
       {
       
$title $row2['headline'];
       echo 
'<li>';
       echo 
$title;
       } 
//if

            
}//foreach     

}//foreach