This challenge will teach you, how to shove tokens down a contract's throat, even if the contract isn't necessarily accepting them.

The goal of this level is to make the balance of the contract greater than zero.

Background

Usually, a contract receives ether, in a payable function or the receive function, or the good ol' fallback function. But what if a contract has none of it?

There are three more unheard-of ways to do this:

1. selfdestruct(): We will talk about this more, in the challenge. This little thing has created a lot of security problem.

2. A contract can also receive Ether as a recipient of a miner block reward.

3. We can also deposit funds into an address before it is deployed, since we can pre-calculate the contract address before it is generated.

In this challenge, we would use selfdestruct() , this function removes a contract from blockchain. Note: This isn't equivalent to deleting stuff from your hard drive, your past transactions etc., will remain on the blockchain.

It looks like this:

selfdestruct(_address);

Whenever this function is called, the ether in the contract will be forcefully sent to the _address mentioned in the argument.

Code of Importance - or the Lack of it.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract Force {/*

                   MEOW ?
         /\_/\   /
    ____/ o o \
  /~____  =ø= /
 (______)__m_m)

*/}

This is an empty contract, without any functions, fallbacks, or constructors. I mean the cat is cute though, but doesn't really help.

The plan of action would be to create a contract, get some goerli, or sepolia in it, and self-destruct it to this address.

Solution

• Open Remix.

•   // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
  
    contract WillSelfDestruct {
        constructor() payable {
        }
        function shovesEther(address _EthernautContractAddress) public {
            selfdestruct(payable(_EthernautContractAddress));
  
        }
    }
    //code is self explanatory.
  

• Compile and Deploy this with '1000000' Wei, or any value for that matter.

• In the "Deployed Contract" section in the "Deploy and run" section, put your instance address as the _EthernautContractAddress

• Run the shovesEther function.

• Submit Instance.

Force✅