Lesson 2: How can you simply pass and address to SimpleStorage without instantiating it?

[tschnide]

Hi, in lesson 2 at about 2:19:00 in the video it goes over this function:

    function sfStore(uint256 _simpleStorageIndex, uint256 _simpleStorageNumber) public {
        SimpleStorage(address(simpleStorageArray[_simpleStorageIndex])).store(_simpleStorageNumber); 
    }

I'm curious about what's happening in the body of the function here
SimpleStorage(address(simpleStorageArray[_simpleStorageIndex])).store(_simpleStorageNumber);

Since it's storing the number using the .store function from SimpleStorage, it seems that passing the address to SimpleStorage creates a new instance of SimpleStorage. How can you just call SimpleStorage without the new keyword or anything? Can you just pass an address to any contract like this and then interact with the contract stored at that address? Thanks for any help you can provide!

[cromewar]

Hello @tschnide sorry for the late reply.
You don't need to use new each time, as you are using this:
SimpleStorage[] public simpleStorageArray;

which already declares the array of contract SimpleStorage, and also you are not assigning that instance to a new variable you are assigning the instance to the array.