Smart Contract Requirements and Architecture BBLC Practice Questions (Page 1)

Questions 1–5

1. 1foundation · easy

   Which security best practice helps mitigate reentrancy attacks in a smart contract that transfers Ether?

   • AUpdating the contract's state before making the external call
   • BUsing tx.origin for authentication
   • CAvoiding the use of require statements
   • DMaking all functions public
   Reveal Solution Discussion Select an answer first
2. 2application · medium

   A team is designing a smart contract for a ticketing system where each ticket has a unique ID, an owner, and a status (available, reserved, sold). The contract must support high-volume ticket purchases. Which data structure is most appropriate for storing ticket data?

   • AA single struct that holds all tickets in a nested array.
   • BA mapping from ticket ID to a struct containing owner and status.
   • CAn array of structs where each element contains the ticket ID, owner, and status.
   • DA mapping from owner address to an array of ticket IDs.
   Reveal Solution Discussion Select an answer first
4. 3foundation · easy

   What is the purpose of using a local blockchain like Ganache during smart contract testing?

   • ATo store off-chain data
   • BTo simulate a blockchain environment for fast and controlled testing
   • CTo mine new cryptocurrencies
   • DTo deploy contracts to the mainnet
   Reveal Solution Discussion Select an answer first
5. 4application · medium

   A team has written a smart contract for a token sale. Before deploying to mainnet, they want to validate that the contract behaves correctly under various conditions, including edge cases and potential attack vectors. Which testing strategy should they adopt?

   • AAsk a colleague to manually review the code and then deploy to mainnet.
   • BWrite unit tests for each function and run them on a local development blockchain, then deploy to a public testnet for integration testing.
   • CDeploy directly to mainnet and monitor the contract for a week to see if any issues arise.
   • DUse only a static analysis tool to scan the code for vulnerabilities and skip runtime testing.
   Reveal Solution Discussion Select an answer first
6. 5application · medium

   A real-estate company wants to tokenize property ownership on a blockchain. They need to define who can list a property, who can transfer tokens, and what data is stored on-chain. Which requirement-elicitation activity is most critical to perform first?

   • AInterview stakeholders to document functional requirements such as listing, transferring, and verifying ownership, and non-functional requirements like security and compliance.
   • BWrite the smart contract code first and then ask stakeholders to review it.
   • CImmediately design the smart contract architecture based on common real-estate tokenization patterns.
   • DChoose the blockchain platform and consensus mechanism before talking to stakeholders.
   Reveal Solution Discussion Select an answer first