pragma solidity 0.4.24; // Testing Uint256 underflow and overflow in Solidity contract UintWrapping { uint public zero = 0; uint public max = 2**256-1; // zero will end up at 2**256-1 function zeroMinus1() public { zero -= 1; } // max will end up at 0 function maxPlus1() public { max += 1; } } 0.7.1