Web3 - Solidity - 101

1. WEB3 - Solidity -
How to write a
smart contract

2. Whoami
My name Yossi Gruner
● I am a solidity and blockchain
developer since 2017
● Sirin Labs
● Finger Foods
● Unity
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3. ▪ ICO
▪ ERC20
▪ ERC721
▪ ERC1155
▪ Multisig
▪ Voting
▪ TokenTimelock
▪ Marketplace (NFTs)
▪ Games
▫ Lottery
▫ Price Prediction
▪ Donation Coin
Examples
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4. ▪ A smart contract is a computer program or a transaction protocol that is intended to
automatically execute, control or document events and actions according to the terms of a
contract or an agreement
What is a smart contract?
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5. ▪ Solidity is a contract-oriented, high-level language for implementing smart
contracts
▪ It was influenced by C++, Python and JavaScript and is designed to target the
Ethereum Virtual Machine (EVM)
▪ Solidity is statically typed, and supports inheritance, libraries and complex defined
types among other features
▪ The code is written in .sol files
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Solidity - Language to write a smart
contract

6. ▪ Contract
▪ Solidity compiler - scol
▪ Bytecode - binary
output
▪ ABI - Application binary
interface
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Solidity - Compiler scol

7. ▪ Remix Web tool - Web browser based IDE
▪ Truffle
▪ Hardhat
In all development environments we can
▪ Write solidity smart contracts
▪ Test smart contracts
▪ Deploy smart contracts
▪ RunPlay with smart contracts
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Development environment write smart contract

8. Hardahat
Ethereum development environment for professionals

9. ▪ Single-line comment - //
▪ Multiline comments /* and */
▪ Natspec - ///
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Solidity Basic - Comments

10. ▪ Import <FILE_NAME_LOCATION>
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Solidity Basic - Impots

11. ▪ Import variables in programming refer to a storage location that
contains values. These values can be changed during runtime
▪ State variables that are permanently stored in the ethereum ledger
by minders
▪ Stage variables store the current values of the smart contract
▪ The allocated memory for a state variable is statically assigned and it
cannot change (the size of the memory allocated) during the lifetime
of the contract
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Solidity Basic - State variables

12. ▪ Internal - this variable can only be used within the current contact
functions and any contact that inherits from them
int internal StateVariable;
▪ private
int private StateVariable;
▪ constant - the qualifier makes state variables immutable
bool constant NFT_PRICE=1;
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Solidity Basic - State variables access

13. ▪ Bool
▪ unit/int
▪ Bytes
▪ Address
▪ Mapping
▫ Key-value table (based on keccak256 hash)
▪ Enum
▪ Struct
▪ Bytes/String
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Solidity Basic - Data types

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Solidity Basic - Functions

15. ▪ public - Anyone can call this function
▪ private - Only this contact can call this function
▪ view/constant - This function will returns data and does not modify
the contract data or state
▪ pure - ensure that they not read or modify the state
▪ payable - when someone call this function they must send ether
along
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Solidity Basic - Function Types

16. ▪ Solidity support declaring a constructor within a contract.
▪ Constructors are optional in solidity and the compile induces a
defaulting contractor when no contact is explicitly defined
▪ The contractor is executed once while deploying the contract
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Solidity Basic - Constructors

17. ▪ In Solidity, a modifier is always associated with a function
▪ A modifier in programming language refers to a construct that
changes the behaviour of the executing code and validates the state
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Solidity Basic - Modifiers

18. ▪ If else
▪ while
▪ do while
▪ for
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Solidity Basic - Conditions & Loops

19. ▪ Solidity supports inheritance between smart contracts
▪ Inheritance is the process of defining multiple contracts that are
related to each other through a parent-child relationship
▪ Solidity support multiple types of inheritance including multiple
inheritances
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Solidity Basic - Inheritance

20. ▪ You can have multiple from of functions
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Solidity Basic - Polymorphism

21. Let's do some coding
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22. ▪ Write some code
▪ Compile it
▪ Deploy it
▪ Verify it
▪ Play with it
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What we are going to do

23. Hello World

24. “
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25. “
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Yossi Gruner

26. We are using
openzeppelin
Ethereum development environment for professionals

27. ERC-20 - Token

28. ▪ Ethereum Request for Comment 20 (ERC-20) is the implemented
standard for fungible tokens created using the Ethereum blockchain.
▪ in other words, they have a property that makes each Token be
exactly the same (in type and value) as another Token. For example,
an ERC-20 Token acts just like the ETH, meaning that 1 Token is and
will always be equal to all the other Tokens.
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What is ERC-20

29. Let's do some coding
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30. ERC-721 - NFT

31. ▪ Ethereum Request for Comments (ERC) 721 is a data standard for
creating non fungible tokens, meaning each token is unique and
cannot be divided or directly exchanged for another ERC-721 token.
▪ The ERC-721 standard allows creators to issue unique crypto assets
like NFTs via smart contracts.
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What is ERC-721

32. Let's do some coding
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33. ▪ Pow Vs Pos
▪ Ethereum internals
▪ Uniswap
▪ SubGraph
▪ ChainLink
▫ Random
▫ Data Provider
▫ Jobs
▪ Testing
▫ Code Coverage
▫ Logging
▪ Web3 Application
▪ Tenderly
=
More Topics for next session
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▪ ERC-1155
▪ Opensea
▪ IPFS
▪ Proxy smart contracts
▪ Marike tree
▪ Metamask
▪ Wallets
▫ Cold vs Hot

34. THANKS!
Any questions?
You can find me at:
yossigruner@gmail.com
https://github.com/yossigruner/Solidity101
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