How to call a non-public variable within a contract?

[andreachello]

This example

async function getGreeting(vm: VM, contractAddress: Address, caller: Address) {
  const sigHash = new Interface(['function greet()']).getSighash('greet')

  const greetResult = await vm.evm.runCall({
    to: contractAddress,
    caller: caller,
    origin: caller, // The tx.origin is also the caller here
    data: hexToBytes(sigHash),
    block,
  })

  if (greetResult.execResult.exceptionError) {
    throw greetResult.execResult.exceptionError
  }

  const results = AbiCoder.decode(['string'], greetResult.execResult.returnValue)

  return results[0]
}

doesn't work if instead of using a function i try to put in a variable name. How can I call a variable?

[jochem-brouwer]

I don't understand what you mean by "putting a variable name", could you post an example or description what you are trying to do? 😄

[andreachello]

Yeah, sorry should have clarified, I mean if you have a variable in a contract like:

contract Example {
    uint public a = 12;
}

in order to get the value in the variable we can do

const sigHash = new Interface(['function a()']).getSighash('a')

only if it is a public variable. Is there a way to get the value of the variable even without declaring it as a public variable, like getStorageAt?

[jochem-brouwer]

No, you cannot do that via evm.runCall. It is not possible to read "private" variables within the EVM. But, it is indeed possible outside the EVM via getStorageAt RPC calls.