added default image

app/design/frontend/Sm/shop4u/Magento_Catalog/templates/product/list.phtml

@@ -31,19 +31,22 @@ $_config            = $this->helper('Sm\Shop4u\Helper\Data');
     $subCats = $subCategory->getChildrenCategories();
     $_helper = $this->helper('Magento\Catalog\Helper\Output');    
 ?>
-<?php if($catId == 206): ?>
+<?php if(($catId == 206) || ($catId == 213)): ?>
 <div class="category-product products wrapper grid products-grid">
  <ol class="products list items product-items row">
     <?php
     foreach ($subCats as $subcat) {
         $_category = $objectManager->create('Magento\Catalog\Model\Category')->load($subcat->getId());
         $subcaturl = $subcat->getUrl();
-        $_imgHtml = '';
-
+        $_imgHtml = '';        
         if ($_imgUrl = $_category->getImageUrl()) {
             $_imgHtml = '<img src="' . $_imgUrl . '" />';
             $_imgHtml = $_helper->categoryAttribute($_category, $_imgHtml, 'image');
-        } ?>
+        }else{
+          $defaultCategoryimg = $this->getViewFileUrl('Magento_Catalog::images/product/placeholder/thumbnail.jpg');
+          $_imgHtml = '<img src="' . $defaultCategoryimg . '" />';
+          $_imgHtml = $_helper->categoryAttribute($_category, $_imgHtml, 'image');
+        }?>
         <li class="item product product-item">
           <div class="product-item-info" data-container="product-grid">
               <div class="item-inner">