Smart contracts

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Smart contracts are programs which govern the behaviour of accounts within the Ethereum state.

In other words they can be treated as the server-side code with different API endpoints (functions) people can hit.

Practically the basis of most smart contracts is:

• read functions
• write functions
• change the state-variables

Smart contracts are lines of code that automatically execute a function when given an input — just like a vending machine.

Smart contracts are immutable by design. Once they are deployed, they stay in their state permanently. Changing a contract requires a full redeploy. The redeploy also resets all the variables since newly deployed contract is treawted a brand new contract.

New contract means new address, and both address and ABI have to be updated on the _index side.

This can be solved

The immutability ifself is a feature, however some parts of the contract can be deliberately programmed to be changeable (e.g. with the ownable contract).

• Learn and describe how to solve it.

Deployment of the smart contract is considered a transaction.

When we deploy our contract, we tell all miners to add smart contract to the blockchain and to broadcast the contract creation transaction over the whole blockchain.

Once the transaction is mined, it is then broadcasted to the blockchain as a legit transaction. From there, everyone updates their copy of the blockchain.