I don't think it's comparable to Amazon's mark-up. The alternative to Amazon is walmart.com, ebay.com, etc., all of which can be directly compared. Instacart provides a delivery service. It's comparable to Uber Eats or Eat24. I agree with the others that it seems shady to provide a delivery service but obfuscate how much you're charging for delivery.
I know Uber Eats bans restaurants from marking up orders placed through them. You can look at your phone and decide exactly how much extra the delivery costs and then decide if it's worth it to not have to go pick up the food yourself. I've never used instacart but if you're telling me that the price of the service is a secret from me I have a problem would that and would not use it. I don't want to pay $50 to have someone pick up my groceries. But I'd gladly pay $10 on certain days. But I have to know beforehand. I'm not going to sit around and hope Instacart doesn't screw me over today.
The utility is that it's a trust-less transfer of value between two parties. Essentially, it's like being able to send cash, anonymously if you chose, to someone else, without an intermediary, in a way that everyone can see and nobody can challenge the legitimacy of.
It seems to me a lot of it is tied up in speculative investment. But there are some vendors who accept it and some countries (eg: Japan) where it's more popular and widely accepted.
I agree but Swift is a new enough language that I'm not sure such a resource exists yet. When I learned Swift I just skimmed through the parts that weren't interesting and that worked for me. It was a good overview of the language.
As an aside, the book, Advanced Swift, by the objc folks is fantastic but assumes you already know Swift. It's not what you're looking for, but something to move onto after you grasp the basics.
I'm not an expert on this but I think the point was market cap is the value of all outstanding shares. Tesla raised money through venture capital while GM raised money by going to the bank and getting a loan.
Think about buying a $1M rental property. One guy gets 9 friends together and they each put up $100k for 10% of the house. The house/business is worth $1m. The market cap is $1m.
Another guy wants to buy a $1m rental property but he goes to the bank and gets a $900k mortgage. The house is worth $1m but the market cap is only $100k.
Since tesla and GM raised money very differently their market caps are not comparable.
It's TDD. Just because the whole app wasn't developed with TDD doesn't mean you can't test drive a bug fix.
There's a bug, you write a test, "this bug shouldn't exist", that test currently fails, then you write just enough code to fix the test, then refactor. That's TDD.
I think TDD helps or doesn't help depending on the circumstances. The problem is the people who claim there's One True Way.
For instance, if you were working on a big app and there was a bug, writing a failing test for that bug and then looking into the fix is very helpful. But if you're starting a new project from scratch with loose requirements, or worse yet, building a prototype, starting with tests would be a waste of time at best.
selection?.organization?.owner is an optional value, meaning it might be nil/null. That "if let" basically says if it's not nil to assign its value to "person" and execute the block. Then inside the block you can treat "person" as a non-optional, known value.