What is Smart Contract

NCKU GDSC Smart Contact study group ( Week 1 )

reference : 「在 2022 年，我們該如何寫智能合約」 on iThome

D1 - D10

Introduction to blockchain ( Ethereum )

D1 : What is block and chain

• Feature :

  • can't by modify
  • decentralized

• Block :

  • Transaction :
    A block contains many transaction . Transaction can be classcify by Create and Execute .
    • Action :
      • Create :
        Deployment of Smart Contract
      • Execute :
        • Recieving Ether
        • Interact with Samrt Contract
    • Properties :
      • Recipient :
        • Address ( The address of recipient )
        • Value
      • Nonce :
        • Counter
      • Signature :
        Sign by private key of sender
      • Value :
        amount of Ether
      • data
        • The most important , send data to contract
      • Gas Limit
      • maxPriorityFeePerGas
      • maxFeePerGas

• Chain :

  • The order of Transaction
    • if the
  • Connecting the block

• Gas :

  • Why :
    Every transaction require computation resources . Base on Fee-For-Service System , the sender account has to pay the fee.
  • Gas ? :
    the Unit that describe computation resources ( describe the any operation cost running on EVM (Ethereum Virtual Machine) )
  • GasLimit :
    The max amount of gas that sender can pay in this transaction . ( Note that , if the GasLimit < the gas that the transaction needs , the transaction will fail( revert ) )

• Fee :

  • BaseFee :
  • Prioroty Fee :
  • Max Fee:
    • Max Fee = Fee per Gas
    • Fee per Gas = BaseFee + Priority Fee
    • The transaction tool will calculate itself
  • Total Fee :
    • Total Fee = Max Fee * Used Gas

• Account :

  • Balance
  • Call
    • can interact with Smart Contract
  • EOA ( Externally-owned account ) :
    • just like our personal acount
    • Balance
    • Nonce
    • Is able to :
      • recive/sende Ether :
      • interact with Contract Account
  • Contract Account :
    • Balance
    • Nonce
    • Codehash
    • storageRoot / storageHash
    • Is able to :
      • recive/send Ether :
      • will only start by EOA

• NetWork :

  • Chain ID :
    • equivalent to Network ID
  • MainNet
  • TestNet :
    • Goerli
    • Sepolia

• Consensus :

  • Miner / Validator :

  • PoW :

  • PoS :

• Intro to Ethereum Stack :

• EIP ( Ethereum Improvement Proposals ) :

  • document that
  • ERC

• ERC ( Ethereum Request for Comments )

  • software interface standard

  • ERC-20

    • Properties :
      • name
      • symbol ( optional )
      • decimals
        • Smaller Unit
        • no float/double in solidity
      • totalSupply
      • balanceOf
        • balance of an address
      • transfer
      • transferFrom
      • approve
      • allowance
    • Events :
      • Transfer
      • Approval
    • Eg :
      • Stable Current : every coin has same value
      • BTC , ETH , USDT
      • Stock

  • ERC-721

    • Non Fungible Token
    • Properites & Events :
      • unique TokenID
    • Metadata Extension :
      • encode json by base64
    • enumeration extension :
      • for other functionalties
    • ERC-721A :
      • a new way to store tokenId and address
      • don't store the same owner name ( if continue )
    • ERC-721R :
      • with time limit

  • ERC-1155 :

    • ERC-1155 = ERC-20 + ERC-721
      • ERC-20 :
        • tokenId = 0 , amount = N
      • ERC-721:
        • tokenID = 1 , amount = 1 ; tokenID = 2 , amount = 1 ; …

• Example of Smart Contract