I have this smart contract to send tokens to multiple addresses:

pragma solidity ^0.4.18;

contract ERC20 {
  function transfer(address _recipient, uint256 _value) public returns (bool success);

contract Airdrop {
  function drop(ERC20 token, address[] recipients, uint256[] values) public {
    for (uint256 i = 0; i < recipients.length; i++) {
      token.transfer(recipients[i], values[i]);

enter image description here

When I access the function "Drop" via MyEtherWallet, I don't know how to insert the addresses in the field "recipients".

I've tried this but none of them work:

0x0000000000000000000000000000000000000001, 0x0000000000000000000000000000000000000002, 0x0000000000000000000000000000000000000003

0x0000000000000000000000000000000000000001 0x0000000000000000000000000000000000000002 0x0000000000000000000000000000000000000003

['0x0000000000000000000000000000000000000001', '0x0000000000000000000000000000000000000002', '0x0000000000000000000000000000000000000003']

["0x0000000000000000000000000000000000000001", "0x0000000000000000000000000000000000000002", "0x0000000000000000000000000000000000000003"]

I can only execute the first one, but it says "Bad Instruction" or "Fail". In the other options I press the button "Write" but nothing happens

  • 2
    Both recipients and values have to be arrays of the same size. Try recipients = ["0x1234..", "0x1234..", "0x1234.."], values = [667, 668, 669]
    – Ismael
    Feb 26, 2018 at 14:53
  • Thank you!! I didn't know that about values... It worked with recipients = 0x1234, 0x1234, 0x1234..... and values = 100, 101, 102.... Without "[]" and without " "" " Feb 26, 2018 at 15:15

2 Answers 2


Both recipients and values have to be arrays of the same size. Try recipients = 0x1234.., 0x1234.., 0x1234.., values = 667, 668, 669. Thanks to Ismael for the answer


This is not an answer to your question but just a heads up, it is not recommended to iterate over transfers but to create a withdraw method. I recommend that you also look at re-entrancy attacks while you're at it and maybe implement some modifiers for safety.

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