Question about Reentrance contract

[danail-vasilev]

I wonder what is the purpose of this line:

      if(result) {
        _amount;
      }

https://github.com/OpenZeppelin/ethernaut/blob/master/contracts/contracts/levels/Reentrance.sol#L22

[justAWanderKid]

short answer is: does nothing. but why it exist?

When You Make a Low Level Call, the an boolean value gets returned, so this is just a way so you dont get warning about not checking the returned value. to understand what i mean, just remove that if statement.

Usually We do this to check if the low level call failed, if yes then revert:

if (!result) { 
    revert("Low Level Call Failed");
}