TypeError: Cannot read property 'eth' of undefined

Question

所以我对这段代码有这个问题，似乎无法弄清楚为什么当我运行使用终端脚本时会出现这个错误：

(node:30800) UnhandledPromiseRejectionWarning: TypeError: Cannot read property 'eth' of undefined

const Web3 = require('web3');

class TransactionChecker{
    web3;
    account;

    constuctor(projectId, account){
        this.web3 = new Web3(new Web3.providers.HttpProvider('wss://mainnet.infura.io/ws/v3/' + projectId));
        this.account = account.toLowerCase();
    }

    async checkBlock(){
      let block = await this.web3.eth.getBlock('latest');
      let number = block.number;
      console.log('Searching block ' + number);

      if (block != null && block.transactions != null){
        for (let txHash of block.transactions){
          let tx = await this.web3.eth.getTransaction(txHash);
          if (this.account == tx.to.toLowerCase()) {
            console.log('Transaction found on block: ' + number);
            console.log({address: tx.from, value: this.web3.utils.fromWei(tx.value, 'ether'), timestamp})
          }
        }
      }
    }
}

let txChecker = new TransactionChecker('6bad75506d6649428e0e34ba41d51805', '0x9cad169749bBF8a3Fd735B26C21F2C7F4D8c5383');
txChecker.checkBlock();

任何对此有更好理解的人都可以提供帮助吗？谢谢

Answer 1

您在 constuctor 中有拼写错误，因此 this.web3... 行永远不会运行。正确的是 constructor.

在你的代码中还有一个问题，当你使用websocket时，你不需要使用HttpProvider只需将websocket url传递给web3:

this.web3 = new Web3('wss://mainnet.infura.io/ws/v3/' + projectId);

TypeError: Cannot read property 'eth' of undefined

TypeError: Cannot read property 'eth' of undefined

ethereum

web3

ether