This is probably a stupid question, but...

I've only been using JASS for a little while, so I'm not how to fix this.
Every time I use the code


I get an error saying "Cannot convert integer to item"
But if I use


It works every time.
Can someone tell me what it is actually doing and how to fix it?
It would be much appreciated. Thank you.

native UnitAddItem takes unit whichUnit, item whichItem returns boolean
This function takes an item for second argument.

'I000' is not an item. It is an integer, it is just a number, an item type id.

function UnitAddItemSwapped takes item whichItem, unit whichHero This also takes an item, are you sure it works?