class 5.txt

step1: 

open the url below and download electrum wallet app image file
	
	https://download.electrum.org/4.1.2/ (electrum-4.1.2-x86_64.AppImage)
        
        click the show in folder option

        right click and open in terminal  

	sudo chmod 777 electrum-4.1.2-x86_64.AppImage
 	
	./electrum-4.1.2-x86_64.AppImage --testnet



./electrum-4.1.2-x86_64.AppImage --testnet

https://coinfaucet.eu/en/btc-testnet/

spy outer keep load conduct autumn discover friend wolf voice rib fortune

series trash surge avocado swim curtain wet caution paddle lonely riot card



BTC ---->  0.000011 btc

mBtc ----> 11 mbtc

0.2 +0.08 ==> 0.28 btc



Ethereum Blockchain:
--------------------

Token contract ---> banks for transfer


solidity 0.4.8

contract Tokencontract {

 createtoken()
 transfertoken()
 checkbalance()
 duplicate check()
 addressvalidation()

}

 account id char
 account balance unit256
 name       char


function createtoken(token id, no of tokens)

{

}


}

Deploy --> tokencontract.sol  ---> it generates unique address --->  008098909870878907098798


1 contract will  have only 1 address ---->

contract address ---> 008098909870878907098798
                 ---> 98098-909-09-08-09900980 

{ 

  user1

  user2
 
  user3
}


each and every contract will consume gas fee

100 function calls ---> 100 eth

200 function calls ---> 200 eth


Ethereum Virtual Machine:
-------------------------

Ethereum Blockchains --> Smart contract --> solidyty --> ethereum blockchain --> EVM ---> LInux/windows/OS

Java Virtual Machine --->





solidity 0.4.8

contract Tokencontract {

 createtoken()
 transfertoken()
 checkbalance()
 duplicate check()
 addressvalidation()

}

 account id char
 account balance unit256
 name       char


function createtoken(token id, no of tokens)

{

}


}


save as tokencontract.sol
compile ---> bytecode --->860987909870987-90809=-089=-09-0896753421234567890-09876543234567890-09876543456879809-0

EVM ----> executing instructions

EVM converts the solidity byte code to OPCODE understod by the machine

OP CODE :
--------

MOVE 'createtoken' to MEMADDRESS1
MOVE 'transfertoken' to MEMADDRESS2



5 func ----> 21000

10 func ----> 42000

Gas price is paid in ethers

txn fee = gas fee * gas limit

createtoken ---> 10 read and wrtite operations ---> 10000 gas ----> 10000 * gas price ---> 10000 * 20 ===> 200000

checkbalance ---> 5 read ops ----> 5000 gas ----> 5000 * 20 ==> 10000


Travel from MP ---> Guj ---> vehicle

vehicle:

 Fuel  (100 ltrs) - gaslimit (100 instructions in ur smarct contract)
 Fuel price (110 INR)     - gas price -- 110

txn = 100 * 110 = 110000 (mar 11)
    = 100 * 150 = 150000 (mar 13)







ERC20 --- fungible token standarsd  ---> crypto currency --> EIP-20

ERC721 --- NFT                       ---> digital assets --> EIP-721

How to write contract:
------------------------

1. specify license
2. include the compiler option
3. specify the contract name
4. write functions
5. declare any variables if needed




Byte code:
----------

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

ABI----> contract specification (application binary interface)


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






[
	{
		"inputs": [],
		"name": "read",
		"outputs": [
			{
				"internalType": "uint256",
				"name": "",
				"type": "uint256"
			}
		],
		"stateMutability": "view",
		"type": "function"
	},
	{
		"inputs": [
			{
				"internalType": "uint256",
				"name": "num",
				"type": "uint256"
			}
		],
		"name": "store",
		"outputs": [],
		"stateMutability": "nonpayable",
		"type": "function"
	}
]



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



gas --->

transaction cost ---> cost/gas associated for txn either read/write to blockchain

execution cost -----> it includes no of operations required for the txn execution



Storage contract:
-----------------

1. spdx license
2. specify the compiler
3. contract name
4. function
5. any variblaes if used






reference links:

1. https://ethereum.org/en/eips/