Smart Contracts

Question 1

Whats is Blockchain

Answer 1

distributed database that maintains a growing list of ordered records called blocks.

Question 2

How are Blocks linked

Answer 2

Uisng cryptography. Each block contains a hash of the previous block, a timestamp, and transaction data.

Question 3

Smart Contract

Answer 3

Self-Executing contract with terms directly written into code

Question 4

Smart Contract (Automation?)

Answer 4

Automatically enforces rules and conditions once pre-defined criteria are met

Question 5

Key Features (Smart Contract)

(AIDT)

Answer 5

Automation
Immutable: Once deployed, can’t be altered
Decentralised
Transparent and Secure

Question 6

Smart Contract Workflow

(WDLER)

Answer 6

1: Written
2. Deploy
2: Listen
3: Execute
4: Record

Question 7

Registry

Answer 7

Record of all deployed contracts, allowing access, and updates

Question 8

Registry (Contains)

Answer 8

bytecode,
ABI,
developer Docs,
critical information

Question 9

Registry (Available)

Answer 9

Available at runtime to all participants

Question 10

Address Book

Answer 10

Used to manage ethereum strings of Hex.

Question 11

Address Book (How it works)

Answer 11

when a new instance of a user or contract is detected it is added to the book with a link to the contract.

all instances of a contract are listed and a REST API for each is auto-generated.

REST API can be used from any node.

Question 12

Truffle

Answer 12

Truffle is an automated testing framework to test smart contracts.

Question 13

Ways to write a test

Answer 13

Javascript and Typescript

Solidity

All files in ./test directory

Truffle will only run .js, .ts, .es, .es6, .jsx, and .sol.

Question 14

Encryption

Answer 14

The use of a key to encode information so that it cannot be read by nodes without the corresponding decryption key.

Question 15

Components of smart contract

Answer 15

Pragma directive: solidity compiler version.

Contract Definition: Basic buildign block

State variables: variables

Functions: Blocks of code defining the operations and logic

Modifiers: custom conditions used to modify behaviour of functions

Events: logging mechanisms

Fallback and Receive: Special functions to handle Ether transfers

Data Types: Defines the type of variables

Question 16

Testing Steps
(WCTDM)

Answer 16

1. Writing
2. Compiling
3. Testing
4. Deploying
5. Monitoring

Question 17

Truffle

Answer 17

Development framework for smart contracts.

Simplifies development.

Question 18

Benefits of Truffle
(ATM)

Answer 18

Automation: automates compiling, deployment, and testing

Testing: Provides testing frameworks (Mocha/Chai)

Migration: Helps manage contract migrations.

Question 19

Gas

Answer 19

Gas is the unit that measures the computational work required to execute transactions and smart contracts on ethereum.

Question 20

Gas (How it works)

Answer 20

Each operation costs a certain amount of Gas.

Users pay gas (Ether) to incentivize miners to process transactions.

Question 21

Gas Limit and price

Answer 21

Limit: the amount of gas a user is willing to spend

Price: the amount a user is willing to pay in ether for each unit of Gas

Question 22

Artifacts.required()

Answer 22

Helps JavaScript code find and interact with a specific smart contract that you’ve already compiled.