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Java

Posted by Sebastian Röder
Sebastian Röder
13,878 Points

For consistency, `getItemName()` for an empty bin should return an empty string.

After the video we have the following code in Bin.java:

    public String getItemName() {
        if (isEmpty()) return null;

        return items.peek().getName();
    }

    public int getItemPrice() {
        if (isEmpty()) return 0;

        return items.peek().getRetailPrice();
    }

The behaviour of the two methods is not consistent. The methods should either both return null or both return a "known good" value when the bin is empty. When the price for an empty bin is 0, I suppose the item name for an empty bin should be "" (the empty string), or maybe even better the string "Empty".

Imagine our vending machine has a display to show an item’s name and price. When the bin is empty, the machine should still be able to display something sensible there.

    public String getItemName() {
        if (isEmpty()) return "";

        return items.peek().getName();
    }

    public int getItemPrice() {
        if (isEmpty()) return 0;

        return items.peek().getRetailPrice();
    }

1 Answer

Pedro Cabral
Pedro Cabral
33,586 Points
Pedro Cabral
Pedro Cabral
33,586 Points

Nice catch! Speaking of which, I think it might harm whoever calls the getter because there is a chance of being thrown a NullPointerException down the road.