迭代遍歷一個Foreach循環

Question

我想遍歷這個foreach中的一個數字，所以像'item_name_'。 $我...但我不知道該怎麼做？你能幫我一下嗎？

$cart = $this->cart->contents(); 
    foreach ($cart as $item){ 
     $this->paypal_lib->add_field('item_name_1', $item['name']); 
     $this->paypal_lib->add_field('amount_1', $item['subtotal']); 
     $this->paypal_lib->add_field('item_number_1', $item['id']); 
     $this->paypal_lib->add_field('quantity_1', '1'); 
    } 

Answer 1

// initialise variable: 
    $i = 0; 

    $cart = $this->cart->contents(); 
    foreach ($cart as $item){ 
     $i++; 
     // do what you want with the counter variable '$i'. 

     $this->paypal_lib->add_field("item_name_$i", $item['name']); 
     $this->paypal_lib->add_field("amount_$i", $item['subtotal']); 
     $this->paypal_lib->add_field("item_number_$i", $item['id']); 
     $this->paypal_lib->add_field("quantity_$i", '1'); 
    }