(Mastering) Solidity, the Ethereum Programming Language

Here, I give an overview of the contents of the course.

Here, I briefly explain my background.

Here, I explain how I intend to keep this course up to date.

Here, I give an overview of the other presentations in this chapter.

In this presentation, I explain basic blockchain concepts.  I explain:

• what a blockchain is

• how blocks in a blockchain refer to each other

• how a blockchain can be made immutable

• the role of validators

In this presentation, I explain consensus mechanisms used by blockchains.  I explain:

• what a consensus mechanism is

• Proof of Work (PoW)

• Proof of Stake (PoS)

• Proof of Authority (PoA)

• I will compare PoW, PoS and PoA with each other

This test checks your knowledge about blockchains as explained in the "Blockchain Basics" and "Consensus Mechanisms" presentations.

In this presentation, I explain how blockchains are used in practice.  I explain:

• how public and private blockchains are used

• Bitcoin (the biggest public blockchain)

• Ethereum (the second biggest public blockchain)

• how Ethereum will evolve over time

• how costs are calculated when you write to the Ethereum blockchain

In this presentation, I explain how you can invest on the Ethereum blockchain.  I explain:

• what fungible tokens are

• what stablecoins are

• how fungible tokens are traded in liquidity pools

• what permanent or impermanent loss is in a liquidity pool

• what non fungible tokens (NFTs) are

• how you can invest in Ether and earn interest through a staking pool

In this presentation, I refer to a demo that illustrates how a blockchain works from a technical point of view.

The demo illustrates how Bitcoin works:

• the demo illustrates a proof of work consensus mechanism

• the demo illustrates how payment transactions are stored on the blockchain

Ethereum is a little bit different:

• it uses a proof of stake consensus mechanism instead of proof of work

• it stores programs instead of payment transactions

Here I refer to the Bitcoin White Paper.

Here I refer to the Ethereum White Paper, Yellow Paper and Beige Paper.

Here, I give an overview of the contents of this chapter.

Here I explain how to install npm, which is required for development

Here I show the website of Truffle Suite and Hardhat, 2 popular development environments for Solidity.  We will be using Hardhat in this course.

Here I show how to set up Hardhat.

Summary of the Hardhat Setup video

Here I show where you could download the editor I will be using in this course: Visual Studio Code. This is for information only, you can use another editor!

Here we take a look at the sample project generated by Hardhat.

Here I compare the Visual Studio Code extension for Solidity made by Juan Blanco with the one made by the Nomic Foundation.

Here I show some webpages with information about the ERC-20 standard and the GitHub repository of OpenZeppelin, which contains a standard implementation of the ERC-20 standard.  We will extend this standard implementation to create our own cryptocurrency in this chapter.

Here I show how we create our own cryptocurrency in Solidity.

Summary of the A First Contract video

Here I show how we can interact with code deployed on the Ethereum blockchain.

Here I show how we can test our first Solidity smart contract.

Summary of Testing Our First Contract video

Here I explain that the maximum size of a compiled smart contract deployed to the Ethereum blockchain is 24 kB and I explain how you can get around this limit.

Here I explain how you can test the size of your compiled smart contracts.

Summary of Test Contract Size Limit video

Here I gave an overview of what can be configured in Hardhat.

Here I show:

• how we can enable the optimizer in the Hardhat config and

• how we can add blocks to the Hardhat test blockchain in intervals. By default, blocks are written instantly to the Hardhat test blockchain each time you write to the blockchain. This is not how Ethereum works. In Ethereum, blocks are not added instantly, but in intervals.

Here I warn against some sloppy code I wrote in the previous video, which may work fine for tests that use Hardhat, but which is not guaranteed to work fine in production.

Here I show how you can log messages from your Solidity code to a console window.

Here I show how you can configure Hardhat to use web3.js.

Here I show how the ethers.js code of the contract size test is changed to web3.js code.

Here I show how the ethers.js code of the SeedToken unit tests is changed to web3.js code.

Here I give an overview of the main development tools that are available to develop for the Ethereum blockchain: Hardhat Runner, Hardhat Network, Hardhat VSCode, Truffle, Ganache, Truffle for VSCode, ethers.js and web3.js

Here, I give an overview of the contents of this chapter.

Here I show the website of MetaMask.  We will be using MetaMask as the wallet in which we store our ethers and cryptocurrencies and from which we make payments if we want to execute a function that writes to the Ethereum blockchain.

Here I show how to install and set up MetaMask.

Here I explain in more detail what a secret recovery phrase is.

Here I show how you can set up a Hardhat test blockchain and how you can connect MetaMask to it.

Here I show how you can initialize a Hardhat test blockchain with JavaScript code.

Here I execute the scripts to initialize a Hardhat test blockchain.

Here we check with MetaMask that the Hardhat test blockchain is initialized with the script shown in the previous 2 videos.

Here I show an issue for sending cryptocurrencies on a Hardhat test blockchain with MetaMask: MetaMask does not have a valid gas estimate and therefore does not allow sending cryptocurrencies.  I show how to fix this issue.  This issue does not exist on the real Ethereum blockchain.

Here I show how you can send cryptocurrencies from a MetaMask wallet on a Hardhat test blockchain.  You can send cryptocurrencies in the same way on the real Ethereum blockchain.

Here I show how you can clear the activity from a MetaMask account.  If you reinitialize a test blockchain, you also have to reinitialize the MetaMask accounts used on that blockchain by clearing the activity of the accounts.  It is not needed to clear the activity of an account on the real Ethereum blockchain, because the Ethereum blockchain is never reinitialized and keeps all history.

Here, I explain how you get ethers for the Ethereum mainnet and the Sepolia test blockchain.  I also explain how to configure Ethereum blockchain networks in Hardhat and when to use them or when to use a local test blockchain.

Here I show how to configure Hardhat to interact with the Sepolia test blockchain.  You configure Hardhat the same way to interact with the Ethereum blockchain.

Here I show how the Infura API key and the private keys of the accounts you add to a Hardhat configuration file look like and how you get these values.  The private keys of the accounts have to be preceded by '0x' to denote that they are hexadecimal numbers.

Here I show how you can recover your MetaMask wallet.

Here, I give an overview of the contents of this chapter.

Here I give an introduction to the Remix integrated development environment that can be used as an alternative to Visual Studio Code and Hardhat.

Here I show how you can access the file system with the Remix web application.

Here I show how you can run Remix as a desktop application, which solves the issue of accessing the file system, but introduces another issue: the Remix desktop application does not have browser extensions such as MetaMask.  I show how you can circumvent the absence of MetaMask with WalletConnect.

Here I explain that Visual Studio Code and Hardhat manage Solidity dependencies better than Remix.

Here I show a factory smart contract that will create instances of our cryptocurrency smart contract and I also show how you can deploy this smart contract to the blockchain through Remix.

Here I show how you can register an Ethereum Name and how you can link it to an Ethereum address, such as the address of a smart contract.