[Ethereum] Problem with truffle console : Cannot read property ‘call’ of undefined

contract-developmentsoliditytestrpctruffle

I have a problem when executing the code

HelloWorld.deployed().balance.call().then(console.log)

This error introduced: Cannot read property 'call' of undefined
This problem is similar to this thread but it does not help on my case.

Thanks for your help!

My code is from this turorial

contract HelloWorld {
  address public owner;
  mapping (address => uint) balances;
  function HelloWorld() {
    owner = msg.sender;
    balances[owner] = 1000;
  }
  function transfer(address _to, uint _value) returns (bool success) {
    if (balances[msg.sender] < _value) {
      return false;
    }
    balances[msg.sender] -= _value;
    balances[_to] += _value;
    return true;
  }
  function getBalance(address _user) constant returns(uint _balance) {
    return balances[_user];
  }
}

Best Answer

You don't have a method called "balance" but "getBalance" with an address argument "_user", so you need to call it this way:

HelloWorld.deployed().getBalance.call('YOUR_ADDRESS')

Related Solutions

[Ethereum] Problem with Truffle Console: Cannot read property ‘call’ of undefined

If you are running the latest version of Truffle (v.3.x), the way to call a function or variable in your contract has evolved a little bit according to the Upgrading documentation

In Truffle 2.0, your contract abstractions managed your networks in a naive way, and added constructs like a "default network" that opened up the possibility of using the wrong network artifacts and deployed addresses at the wrong time. This provided a fancy and easy to use syntax – i.e., MyContract.deployed().myFunction(...) – but it left your code open to errors. Truffle 3.0 changes this syntax, where .deployed() is now thennable, like a promise (see example below). Similarly, this makes your contract abstractions seamlessly integrate with EIP 190, Ethereum's package management standard. All of this is for the better, but it means you'll have some changes to make all across the board.

So in your case, if you want to call a function, you have to do this:

HelloWorld.deployed().then(function(instance) {
    return instance.balance.call();
}).then(function(balance) {
    console.log(balance);
});

Please refer to the latest documentation for more details.

[Ethereum] API to “Read Contract Information” to fetch stats of an ICO

Which version of web3 are you using?

Here is a working example with web3@^1.0.0-beta.34

const Web3 = require('web3');
contractAddress = '0xe7775a6e9bcf904eb39da2b68c5efb4f9360e08c';
provider = 'https://mainnet.infura.io';
const contractAbiJSON = '';//... The JSON abi

// Init
const web3 = new Web3(new web3.providers.HttpProvider(provider));

const contract = new web3.eth.Contract(contractAbiJSON, contractAddress);

contract.methods.totalSupply().call().then((totalSupply) => {
  console.log(totalSupply);
});

Best Answer

Related Solutions

[Ethereum] Problem with Truffle Console: Cannot read property ‘call’ of undefined

[Ethereum] API to “Read Contract Information” to fetch stats of an ICO

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