JavaScript를 사용하여 블록체인 및 디지털 통화를 구현하는 방법

class Block {
  constructor(timestamp, data, previousHash = '') {
    this.timestamp = timestamp;
    this.data = data;
    this.previousHash = previousHash;
    this.hash = this.calculateHash();
  }

  calculateHash() {
    return SHA256(this.previousHash + this.timestamp + JSON.stringify(this.data)).toString();
  }
}

class Blockchain {
  constructor() {
    this.chain = [this.createGenesisBlock()];
  }

  createGenesisBlock() {
    return new Block(0, "Genesis Block", "0");
  }

  getLatestBlock() {
    return this.chain[this.chain.length - 1];
  }

  addBlock(newBlock) {
    newBlock.previousHash = this.getLatestBlock().hash;
    newBlock.hash = newBlock.calculateHash();
    this.chain.push(newBlock);
  }

  isChainValid() {
    for (let i = 1; i < this.chain.length; i++) {
      const currentBlock = this.chain[i];
      const previousBlock = this.chain[i - 1];

      if (currentBlock.hash !== currentBlock.calculateHash()) {
        return false;
      }

      if (currentBlock.previousHash !== previousBlock.hash) {
        return false;
      }
    }

    return true;
  }
}

class Transaction {
  constructor(sender, receiver, amount, fee, time) {
    this.sender = sender;
    this.receiver = receiver;
    this.amount = amount;
    this.fee = fee;
    this.time = time;
  }
}

class Blockchain {
  ...

  pendingTransactions = [];

  minePendingTransactions(miningReward) {
    const block = new Block(Date.now(), this.pendingTransactions);
    block.mineBlock(this.difficulty);
    console.log('Block successfully mined!');
    this.chain.push(block);

    this.pendingTransactions = [
      new Transaction(null, miningRewardAddress, miningReward)
    ];
  }

  createTransaction(transaction) {
    this.pendingTransactions.push(transaction);
  }
}