Solidity: array.push doing strange

[xmanemran]

pragma solidity ^0.4.21;

contract Companys{

    struct Product{
        bytes32 name;
        uint16 price;
    }

    mapping(address => Product[]) products;


    function addProduct(bytes32 _name, uint16 _price){
        products[msg.sender].push(Product({name: _name, price: _price}));
    }

    function getProducts() returns(bytes32[], uint16[]){
        uint productSize = products[msg.sender].length;

        bytes32[] productsName;
        uint16[] productPrices;

        for(uint i = 0; i < productSize; i++){
            productsName.push(products[msg.sender][i].name);
            productPrices.push(products[msg.sender][i].price);
        }

        return (productsName, productPrices);
    }
}

after add one product, when i trey to get products it give me two productsName and productPrices .. :O. Can any one please explain me why?

[chriseth]

productsName and productPrices are invalid storage references. You have to create memory arrays (and create it with the proper size in the first place, memory arrays do not have .push()).