class 7.txt

Smart Contracts:
----------------

business logic/contract agreements whcih can be writen in solidity

 a.) token standards: ERC20, ERC721

when we deploy a smart contract ---> unique contract account (987987907hgkhjgjhgkjgkj)


EVM ---> execution engine which runs the smart contract


GETH address - 0xd41DF0ac0Cf20a2070ee1F4eC5aF4C9816Ab7639


chain id ---> 1 -- mainnet
              5 -- test net
              7 -- test net goelri

              786 ---> private chain id  


when connecting to either Mainnet/test net ---> it captures and sync few blocks from the network

Mainnet ---> block 19000 ---> 2/3 days
testnet ---> blocks 100  ---> 5 mins

DAG is in progress ----> directed acyclic graph (data structure) ---> block syncing process






// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.13;    // include
contract Helloworld {       // class class name
    function helloworld () public pure returns (string memory) {
        return "Hello World";
    }
}



react project:
----------------

 app.js 

 { 

 import abi = abi ('ballot')
 import address = '8098098-09=-09=09-=09-'

 "ballot.sol" ---> smart contract

web ----->             web3.js apis(ABI, smart contract address)  ------------> blockchain

simple practice of web3, truffle frameowkr ----> 


 abi.Proposalvotes (voter name, candidate id)

 {

 }

ABI (application binary interface) ---> gives a birds eye viewof the smart contract



[
	{
		"inputs": [],
		"name": "helloworld",
		"outputs": [
			{
				"internalType": "string",
				"name": "",
				"type": "string"
			}
		],
		"stateMutability": "pure",
		"type": "function"
	}
]














[
	{
		"inputs": [
			{
				"internalType": "bytes32[]",
				"name": "proposalNames",
				"type": "bytes32[]"
			}
		],
		"stateMutability": "nonpayable",/pure/payable/view
		"type": "constructor"
	},
	{
		"inputs": [],
		"name": "chairperson",
		"outputs": [
			{
				"internalType": "address",
				"name": "",
				"type": "address"
			}
		],
		"stateMutability": "view",
		"type": "function"
	},
	{
		"inputs": [
			{
				"internalType": "address",
				"name": "to",
				"type": "address"
			}
		],
		"name": "delegate",
		"outputs": [],
		"stateMutability": "nonpayable",
		"type": "function"
	},
	{
		"inputs": [
			{
				"internalType": "address",
				"name": "voter",
				"type": "address"
			}
		],
		"name": "giveRightToVote",
		"outputs": [],
		"stateMutability": "nonpayable",
		"type": "function"
	},
	{
		"inputs": [
			{
				"internalType": "uint256",
				"name": "",
				"type": "uint256"
			}
		],
		"name": "proposals",
		"outputs": [
			{
				"internalType": "bytes32",
				"name": "name",
				"type": "bytes32"
			},
			{
				"internalType": "uint256",
				"name": "voteCount",
				"type": "uint256"
			}
		],
		"stateMutability": "view",
		"type": "function"
	},
	{
		"inputs": [
			{
				"internalType": "uint256",
				"name": "proposal",
				"type": "uint256"
			}
		],
		"name": "vote",
		"outputs": [],
		"stateMutability": "nonpayable",
		"type": "function"
	},
	{
		"inputs": [
			{
				"internalType": "address",
				"name": "",
				"type": "address"
			}
		],
		"name": "voters",
		"outputs": [
			{
				"internalType": "uint256",
				"name": "weight",
				"type": "uint256"
			},
			{
				"internalType": "bool",
				"name": "voted",
				"type": "bool"
			},
			{
				"internalType": "address",
				"name": "delegate",
				"type": "address"
			},
			{
				"internalType": "uint256",
				"name": "vote",
				"type": "uint256"
			}
		],
		"stateMutability": "view",
		"type": "function"
	},
	{
		"inputs": [],
		"name": "winnerName",
		"outputs": [
			{
				"internalType": "bytes32",
				"name": "winnerName_",
				"type": "bytes32"
			}
		],
		"stateMutability": "view",
		"type": "function"
	},
	{
		"inputs": [],
		"name": "winningProposal",
		"outputs": [
			{
				"internalType": "uint256",
				"name": "winningProposal_",
				"type": "uint256"
			}
		],
		"stateMutability": "view",
		"type": "function"
	}
]