Where my number is stored ?

[akugone]

Hello
Maybe a stupid question, but when i store a number with the storage function, it will store my number in the blockchain.
So if i want to retrieve (view) my number, I'll make a request to a different block than the stored contract block in order to screen my number ?
Contract is stored in a block and my stored number is stored in another block, i'm right ?

[RoboCrypter]

@akugone : Yes, your stored number is stored in the smart contract which is on the blockchain,
and whenever you want to see your no, you call the blockchain and blockchain pulled that number out of your smart contract and present to you.
So your stored Number is in your contract and your contract is on the blockchain.

Hopefully, It will clear your doubt!

[RoboCrypter]

@akugone : You must have a function for example storeNumber, thats why you can update your number.
Unless if you hard code your stored number like immutable or a constant or just storage in those cases, they can not be changed and only be set once.

[akugone]

So if I well understand something stored in a block is not really immutable, we can update it

[RoboCrypter]

@akugone : Check my above answer I have edited it now you will understand better.

[RoboCrypter]

@akugone :
function(uint256 storeNo) public returns(uint256) { return storeNo } : You can update it after deploying the contract.

uint256 public number = 10; : You cannot update it, once its deployed, It is immutable.

[akugone]

Ok thanks :)

[othaime-en]

Hey @akugone when you deploy the contract, your stored number is deployed along with it in the form of a transaction. So if you want to read or retrieve the number, you could go through the transaction history of your contract address and see the data that was deployed with the contract. Alternatively, for public variables like our store value, you can read the value from the contract state in the contract section of etherscan.
Now when it comes to storing a number in our store function, the process of storing is done in a transaction format and all the data is stored as a transaction hash that is not necessarily on the same block as the contract. However, this interaction is recorded and the new value of the store variable changes to a new state. However, it is important to note that the previous value doesn't change or is not deleted, it stays on blockchain. What this new transaction does is saves the state change so you can actually see both the new state (with the new number) and hte old state of the contract

[othaime-en]

[othaime-en]

The before and after in the screenshot above show you the state change that took place when you stored a new number. So once you've stored something on the blockchain, it is indeed immutable. You can never change it.

[akugone]

Nice thanks very much it's pretty clear now :)