I've seen a contract that stores -1 as an unsigned integer.
uint256 can = allowed ? uint256(-1) : 0;
Can anyone explain the benefit of this over something like:
uint256 can = allowed ? 1 : 0;
[Ethereum] the purpose of uint256(-1)
solidity
solidity
I've seen a contract that stores -1 as an unsigned integer.
uint256 can = allowed ? uint256(-1) : 0;
Can anyone explain the benefit of this over something like:
uint256 can = allowed ? 1 : 0;
Best Answer
By 2s-complement,
uint256(-1)is equal to the maximum value ofuint256.So it's essentially a shorter way to write
0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF.For
bool can, your wondering would be correct (i.e.,allowed ? true : falsewould suffice).But since
uint256 canis used, the answer to your question depends on what it is used for...