title: WooCommerce get category slug - Undefined property notice with a function
body: <p>I use this function to convert the woocommerce category id into a category slug</p>
  
  <pre><code>function woocommerceCategorySlug($id){
      $term = get_term( $id, 'product_cat' );
      return $term-&gt;slug;       
  }
  </code></pre>
  
  <p>This is working, but the problem is that i'm getting a notice </p>
  
  <blockquote>
  <pre><code>Notice: Undefined property: WP_Error::$slug 
  </code></pre>
  </blockquote>
  
  <p>Is there a way to avoid this notice?</p>