I am new to solidity and trying to deploy a contract to see whether the address is EOA or Smart Contract. The code is listed below. I am not able to see the boolean value when I executed the contract in the mainnet.

pragma solidity ^0.4.0;
contract Ballot {

event isEOAOrNot(bool val);

function isContract(address addr) returns (bool) {
  uint size;

  assembly { size := extcodesize(addr) }
  bool val = size > 0;
  return val;


3 Answers 3


Here's the best way I know:

  1. Launch contract:

Step 1

  1. Run transaction:

Step 2

  1. View transaction data:

enter image description here

  1. Find the "event" and "args" parameters under logs: enter image description here

And there you have it; the event and the arguments.

  • It's not there. Commented Jun 15, 2018 at 20:28
  • @ErickRobertson if you could provide more details, I will try and see what went wrong. On what step did you get stuck?
    – Nicholas
    Commented Jun 17, 2018 at 19:22
  • It was there for me, this should be the accepted answer.
    – cmikeb1
    Commented Nov 10, 2018 at 17:28
  • This is pretty uncomfortable to have to extract the events from the details like this. Can't it be automated and the events printed below the transaction somehow? Is there a plugin that could do it?
    – Qwerty
    Commented Jan 22, 2022 at 20:28

You've missed the emit when calling the isEOAOrNot(val) event. should be:

emit isEOAOrNot(val);

If you compile a different contract, previous contracts that you deployed will no longer show events. So, recompile the contract you want to see the events for before calling the method.

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