Question

I am developing an app with a shopping cart. When I add a product, I have to check if this product exist. I was using this method:

for (go over all products){

  if(product exists){

  --only change the quantity of the product[n]

  }
  else{

  --create a new product object with all its properties

  }

}

But with this method if the product I want to add don´t is the same with the index 0 (the first that the for checks), always add a new object (product) so if for example, my product exists and have the index 2, this for never will know that it exists.

Sorry for my english 😉 and thank you.

Answer 1

If I understood it right, you’re problem is, that you loop over all the products and if the product is not the same as the new one, you just add a new one.

but you’ll need to loop over all entries first and after you have done that and didn’t find anything, you create a new product.

So in pseudo code:

bool productExists = false;
for every product {
    if(same product) {
        productExists = true
        change the quantity
        break;
    }    
}
if(!productExists) {
    add new product
}