How to convert a uint256 type integer into a bytes32?

Question

Since both types, uint256's and bytes32's space are 2^256. How to map an uint256 type integer into bytes32 type in Solidity ?

Possible duplicate of How to convert a uint to bytes in Solidity? — Richard Horrocks, Jun 24 '16 at 17:26
@RichardHorrocks It doesn't seem to be exactly the same question. — Ismael, Jun 24 '16 at 18:18
I think that if we have bytes32 b and uint256 u, then we can do b = bytes32(u) and u = uint256(b). Sorry, can't check now. — Ismael, Jun 24 '16 at 18:19
I'm being a bit trigger-happy with the dupes. Apologies - I'll reel it in. Credit to @Ismael. — Richard Horrocks, Jun 24 '16 at 22:07

score 18 · Accepted Answer · answered Jun 24 '16 at 21:50

18

Just use bytes32(u). It's as easy as that because they are both 2^256 (unlike bytes).

No need for a separate function, but to clarify:

function convert(uint256 n) returns (bytes32) {
    return bytes32(n);
}

answered Jun 24 '16 at 21:50

eth

1

No longer works in solidity ^0.8.0. – Jan Beneš Jun 13 '22 at 15:26
1

@JanBeneš actually it still works in v0.8 - I used v0.8.15+commit.e14f2714 to compile this code and it worked. – Paul Razvan Berg Jun 28 '22 at 11:59

1 Answers1