Call an existing contract function from truffle console

Question

Let's suppose an existing Ethereum deployed contract.

I know the deployment Address and i have the contract's source code.

What i want to do is to call a function on this deployed contract from truffle console.

Is it possible and how can i do that ?

Thanks

Answer 1

Say you have a contract like the one below deployed at address 0x1f2deF1210B4D06B267A64b9888990734Aba7e24

pragma solidity ^0.8.1;

contract test {
    string public initialString = "Hello World!";

    function getString() public view returns (string memory) {
        return initialString;
    }
}

To create an instance of that contract:

truffle(develop)> contract = await test.at('0x1f2deF1210B4D06B267A64b9888990734Aba7e24')

To call a function:

truffle(develop)> a = await contract.getString()

To check the variable directly (if declared as public):

truffle(develop)> b = await.contract.initialString()

This way, you will have in a and b the expected values.

Of course you need to point to the right Ethereum network within the truffle-config.js file in networks section.