使用此代码：

foreach ( WC()->cart->get_cart() as $cart_item ) {  
   $quantity =  $cart_item['quantity'];
   echo $quantity;
}

我可以获得购物车中添加的所有产品的数量,但我需要特定产品.

解决方法:

你应该试试这个：

// Set here your product ID
$targeted_id = 24;

foreach ( WC()->cart->get_cart() as $cart_item ) { 
    if($cart_item['product_id'] == $targeted_id ){
        $qty =  $cart_item['quantity'];
        break; // stop the loop if product is found
    }
}
// Displaying the quantity if targeted product is in cart
if( ! empty( $qty ) )
    echo '<p>Quantity for Product ID ' . $targeted_id . ' is: ' . $qty . '</p>;