Is it possible to have a mapping with a hash as key?

Question

Is it possible to have a mapping in Solidity with a hash as key?

For example:

mapping (hash => uint) hashToInt;

If not, is there any way to group some information and put it as a key of a mapping?

Answer 1

Yes, hash was an old type that's been replaced with bytes32. You can call keccak256(data1, data2, ...) and use that as a key.

Prior discussion on hash.