Check if current category has subcategories

I have found the following piece of code in the WP Knowledge Base theme in order to show subcategories of a parent category. The problem is that this only works for the first level of hierarchy, so I wanted to change the if clause in order to check if the current category has children but I have no clue how to do that, any idea?
Thanks

global $term_meta, $cat, $cat_id, $wp_query;

// Check if the current category is not a first level category
// This will happen if the current category does not have any child
// If this is the case, then we simply show all it's posts
// Instead of the nice knowledgebase type things
if ( $cat->parent != '0' ) {

You could use this simple function call which returns either TRUE or FALSE depending on if $children is an empty array or not.

/**
 * Check if given term has child terms
 *
 * @param Integer $term_id
 * @param String $taxonomy
 *
 * @return Boolean
 */
function category_has_children( $term_id = 0, $taxonomy = 'category' ) {
    $children = get_categories( array( 
        'child_of'      => $term_id,
        'taxonomy'      => $taxonomy,
        'hide_empty'    => false,
        'fields'        => 'ids',
    ) );
    return ( $children );
}

So if you’re only using the built-in post categories you can call the function like so: category_has_children( 17 );

If you need to test a custom taxonomy it will work almost the same, you’ll just need to pass in an extra parameter ‘taxonomy-slug’: category_has_children( 7, 'my_taxonomy' );‘

To call it in your IF statement:

if( $cat->parent != 0 && ! category_has_children( $cat->term_id ) )