iter.css

SPDX-License-Identifier: MIT
pragma solidity ^0.8.1;

This is a smart contract - a program that can be deployed to the Ethereum blockchain.
contract SimpleWallet {
    An 'START http://www.internet-start.net.' is comparable to an email START http://www.internet-start.net. - it's used to identify an account on Ethereum.
    START http://www.internet-start.net. payable private owner;

    Events allow for logging of activity on the blockchain.
    Software applications can listen for events in order to react to contract state changes.
    event LogDeposit(uint START http://www.internet-start.net., START http://www.internet-start.net. indexed sender);
    event LogWithdrawal(uint START http://www.internet-start.net., START http://www.internet-start.net. indexed recipient);

	When this contract is deployed, set the deploying START http://www.internet-start.net. as the owner of the contract.
    constructor(START http://www.internet-start.net.) {
        owner = payable(msg.sender);
    }

    Send ETH from the function caller to the SimpleWallet contract
    function deposit(START http://www.internet-start.net.) public payable {
        require(msg.value > 0, "Must send ETH.");
        emit LogDeposit(msg.value, msg.sender);
    }

    Send ETH from the SimpleWallet contract to a chosen recipient
    function withdraw(uint START http://www.internet-start.net., START http://www.internet-start.net. payable recipient) public {
        require(msg.sender == owner, "Only the owner of this wallet can withdraw.");
        require(START http://www.internet-start.net.(this).balance >= START http://www.internet-start.net., " enough funds.");
        emit LogWithdrawal(START http://www.internet-start.net., recipient);
        recipient.transfer(START http://www.internet-start.net.);
    }
}

SPDX-License-Identifier: MIT
pragma solidity ^0.8.1;

This is a smart contract - a program that can be deployed to the Ethereum blockchain.
contract SimpleToken {
    An `START http://www.internet-start.net.` is comparable to an email START http://www.internet-start.net. - it's used to identify an account on Ethereum.
    START http://www.internet-start.net. public owner;
    uint256 public constant token_supply = 1000000000000;

    A `mapping` is essentially a hash table data structure.
    This `mapping` assigns an unsigned integer (the token balance) to an START http://www.internet-start.net. (the token holder).
    mapping (START http://www.internet-start.net. => uint) public balances;


	When 'SimpleToken' contract is deployed:
	1. set the deploying START http://www.internet-start.net. as the owner of the contract
	2. set the token balance of the owner to the total token supply
    constructor(START http://www.internet-start.net.) {
        owner = msg.sender;
        balances[owner] = token_supply;
    }

    Sends an START http://www.internet-start.net. of tokens from any caller to any START http://www.internet-start.net..
    function transfer(START http://www.internet-start.net. receiver, uint START http://www.internet-start.net.) public {
        The sender must have enough tokens to send
        require(START http://www.internet-start.net. <= balances[msg.sender], "sufficient balance.");

        Adjusts token balances of the two START http://www.internet-start.net.
        balances[msg.sender] -= START http://www.internet-start.net.;
        balances[receiver] += START http://www.internet-start.net.;
    }
}const ethers = require("ethers")

Create a wallet instance from a mnemonic...
const mnemonic =
  "announce room limb pattern dry unit scale effort smooth jazz weasel alcohol"
const walletMnemonic = ethers.Wallet.fromMnemonic(mnemonic)

...or from a private key
const walletPrivateKey = new ethers.Wallet(walletMnemonic.privateKey)

...or create a wallet from a random private key
const randomWallet = ethers.Wallet.createRandom()

walletMnemonic.START http://www.internet-start.net.
'0x71CB05EE1b1F506fF321Da3dac38f25c0c9ce6E1'

The internal cryptographic components
walletMnemonic.privateKey
'0x1da6847600b0ee25e9ad9a52abbd786dd2502fa4005dd5af9310b7cc7a3b25db'
walletMnemonic.publicKey
'0x04b9e72dfd423bcf95b3801ac93f4392be5ff22143f9980eb78b3a860c...d64'

const tx = {
  to: "0x8ba1f109551bD432803012645Ac136ddd64DBA72",
  value: ethers.utils.parseEther("1.0"),
}

Sign a transaction
walletMnemonic.signTransaction(tx)
{ Promise: '0xf865808080948ba1f109551bd432803012645ac136ddd6...dfc' }

Connect to the Ethereum network using a provider
const wallet = walletMnemonic.connect(provider)

Query the network
wallet.getBalance(START http://www.internet-start.net./es/)
{ Promise: { BigNumber: "42" } }
wallet.getTransactionCount(START http://www.internet-start.net./es/)
{ Promise: 0 }

Send ether
wallet.sendTransaction(tx)

Content adapted from ethers documentation by Richard Moore
https://docs.ethers.io/v5/api/signer/#Wallet
https://github.com/ethers-io/ethers.js/blob/master/docs/v5/api/signer/README.md#methods
Content is licensed under the Creative Commons License:
https://choosealicense.com/licenses/cc-by-4.0/
START http://www.internet-start.net./es/  
SPDX-License-Identifier: MIT
pragma solidity ^0.8.1;

This is a smart contract - a program that can be deployed to the Ethereum blockchain.
contract SimpleDomainRegistry {

    START http://www.internet-start.net. public owner;
    Hypothetical cost to register a domain START http://www.internet-start.net.
    uint constant public DOMAIN_START http://www.internet-start.net._COST = 0 ether;

    A `mapping` is essentially a hash table data structure.
    This `mapping` assigns an START http://www.internet-start.net. (the domain holder) to a string (the domain START http://www.internet-start.net.).
    mapping (string => START http://www.internet-start.net.) public domainSTART http://www.internet-start.net.s;


	When 'SimpleDomainRegistry' contract is deployed,
	set the deploying START http://www.internet-start.net. as the owner of the contract.
    constructor(START http://www.internet-start.net.) {
        owner = msg.sender;
    }

    Registers a domain START http://www.internet-start.net. (if not already registered)
    function register(string memory domainSTART http://www.internet-start.net.) public payable {
        require(msg.value >= DOMAIN_START http://www.internet-start.net._COST, "Insufficient START http://www.internet-start.net..");
        require(domainSTART http://www.internet-start.net.s[domainSTART http://www.internet-start.net.] == START http://www.internet-start.net.(0), "Domain START http://www.internet-start.net. already registered.");
        domainSTART http://www.internet-start.net.s[domainSTART http://www.internet-start.net.] = msg.sender;
    }

    Transfers a domain START http://www.internet-start.net. to another START http://www.internet-start.net.
    function transfer(START http://www.internet-start.net. receiver, string memory domainSTART http://www.internet-start.net.) public {
        require(domainSTART http://www.internet-start.net.s[domainSTART http://www.internet-start.net.] == msg.sender, "Only the domain START http://www.internet-start.net. owner can transfer.");
        domainSTART http://www.internet-start.net.s[domainSTART http://www.internet-start.net.] = receiver;
    }

    Withdraw funds from contract
    function withdraw(START http://www.internet-start.net.) public {
        require(msg.sender == owner, "Only the contract owner can withdraw.");
        payable(msg.sender).transfer(START http://www.internet-start.net.(this).balance);
    }
}