Ethereum Blockchain Solidity Smart Contracts Web3 and Dapps

Explore how Ethereum, introduced in 2015 by Vitalik Buterin, is a decentralized open source blockchain that enables programmable smart contracts and deployed dapps, using Ether for transactions and miner incentives.

Explore how gas costs measure computational effort on the Ethereum network, enabling pricing for transactions and smart contracts, with gas limits preventing failures and guiding consideration of lower-fee EVM networks.

Discover alternative networks for deploying Ethereum smart contracts, such as Binance Smart Chain, Polygon Matic, Fantom, and Optimism, to reduce gas fees and speed up transactions.

Learn to write Solidity code with Remix, deploy to test networks, and manage the SPDX license identifier and Solidity version using a version pragma to prevent mismatches.

Learn to write your first Solidity contract in Remix, declare a public string variable greet set to Hello World, and add comments while exploring data types and visibility.

Explore environment, account, and gas limit in remix, and learn how the virtual machine, demo accounts with ether, and gas costs affect deploying and interacting with smart contracts.

Deploy and interact with a solidity contract in Remix IDE, compile, deploy from an account, view gas and address, and call a public variable to display hello world.

Build a counter contract in remix using solidity with a public unsigned integer count and three functions: increment, decrement, and get, exploring visibility types and gas implications.

Explore Solidity visibility types for state variables—public, private, internal, and why external is only for functions, noting how public generates a getter.

Master function modifiers in Solidity, including view, pure, payable, external, internal, public, and private, to control read/write access, ether handling, and interactions with external data sources and derived contracts.

Explore Solidity primitive data types: boolean, uint, int, and address, and local, state, and global variables, including block.timestamp and message.sender, and how gas applies to state changes.

Learn how to define state and local variables in Solidity contracts, use memory for data locations, and access global variables like block.timestamp and msg.sender.

Debug solidity contracts and web apps faster using google, chatgpt, and Stack Overflow for quick error fixes and code explanations. Understand memory in solidity and common typos that break visibility.

Discover how constants in Solidity save gas with fixed values that cannot be modified, and learn to implement address and unsigned integer constants and a pure function that returns them.

Discover solidity immutable variables, set in the constructor and never modified after deployment. Learn to pass a uint value and use msg.sender to assign the deployer address.

Explain how the Solidity constructor runs once at deployment to initialize immutable state variables. Set the deployer’s address via msg.sender and a provided uint, which remain immutable after deployment.

Build a simple storage contract to read and write a state variable num using set and get functions, deploy it, and observe the initial zero value and gas cost.

Learn about ether and wei, including how one ether equals one with 18 zeros, and how predefined units in Solidity are used in variables and boolean checks.

Explore gas costs in Ethereum smart contracts by examining an infinite loop that consumes gas, depleting ether until the transaction reverts and fees are refunded.

Explore if else logic in Solidity with practical examples: implement a public pure function using if/else and nested ternary operators to return 0, 1, or 2.

Learn how mapping stores key-value pairs in solidity, using address keys and uint values, with get, set, and delete operations on a public mapping.

Explore how nested mappings in Solidity return a second mapping, enabling boolean values via address and uint keys. Implement get, set, and remove operations.

Learn Solidity data structures, including arrays (fixed and dynamic), structs, and enums, with examples on pushing, indexing from zero, nesting structs, and using enums for limited state values.

Explore Solidity data structures, including arrays, structs, and enums, by building a dynamic uint array, pushing values, checking length, and reading items by index in a deployed contract.

Learn how to define a person struct in Solidity, manage an array of people, and implement add, get person name, get person age, and get people count functions in Remix.

Learn enums in Solidity by defining a status with pending, approved, and rejected, validating input with require, and implementing set and get functions for the current status.

Explore call data in Solidity, learn how function arguments travel as call data, and manage a todo list using structs and a 2D array with storage, memory, and call data.

Explain how errors in smart contracts work using require, revert, and assert; show input validation with require, exceptional conditions with revert, and testing with assert.

Explore creating custom errors in Solidity to save gas over require, using the error keyword with arguments like insufficient fee, and compare gas costs between custom errors and require.

Learn how to create and apply function modifiers in Solidity to enforce access control. See how modifiers validate inputs, such as nonzero addresses, and restrict function calls.

Learn to implement function modifiers in Solidity, including only owner and valid address, to secure ownership. Apply the modifiers on a change owner function and verify access control with tests.

Learn how Ethereum smart contracts emit log events to the blockchain, using indexed sender and message, and inspect log fields from, topic, and args across test and emit log functions.

Explore inheritance in solidity using the is keyword to extend contracts and reuse functions. See contracts A and B provide get string and get int, and contract C inherits them.

Explore function override in solidity inheritance by using virtual in the parent and override in the child, as a dog contract changes animal sound to woof.

Learn how interfaces define contract functions as blueprints, enabling interaction with a counter contract. Deploy and import the interface, then use an address to call increment and read count.

Learn to implement payable functions and payable addresses in a Solidity contract, manage contract ownership, deposit ether, and safely transfer ether to a recipient using require checks.

Learn to send ether with address.call.value in Solidity and why transfer and send are discouraged. Set up a development environment to write and deploy contracts with test accounts and Metamask.

Set up a local solidity development environment with hardhat to write, test, and deploy smart contracts and decentralized apps, including npm and node.js setup and project initialization.

Write a counter smart contract in Hardhat by defining a public count, adding get, increment, and decrement functions, and preparing for compilation and deployment.

Compile smart contracts with Hardhat to generate artifacts and cache, exposing the ABI and bytecode; learn how the API enables front-end apps to interact with contracts via web3.

Deploy a smart contract with hardhat by writing a deploy script, loading ethers via getContractFactory, deploying the contract, and logging its local address.

Learn to deploy a contract locally with Hardhat, using the default first test account, retrieve the deployer address from the deployment receipt, and note that mainnet deployments use unique addresses.

Learn how to deploy contracts to different networks with a chosen account, private key, and chain ID in Hardhat, manage balances, and revert to the default account.

Learn to write tests for smart contracts using chai with hardhat, deploying a counter contract, testing get count is zero, incrementing, decrementing, and handling underflow with a revert.

Learn to build a frontend for your Ethereum smart contracts using React and Next.js, interact with locally deployed contracts via Hardhat, and set up a simple npm workflow.

Learn how to interact with the blockchain from a website by connecting a wallet like MetaMask, sign transactions securely, and use ERC-20 tokens with ethereum-based dapps.

Install MetaMask, create a wallet, and write down the 12-word recovery phrase to recover access on any device. Use the testnet and create additional accounts.

Connect to MetaMask from a front end by detecting window.ethereum, requesting accounts, and updating the connect button to reflect connected status.