hash

keccak256 is a cryptographic hash funciton commonly used in Solidity.

Some use cases are:

• Creating a deterministic unique ID from inputs

• Cryptographic signatures

• Commit reveal scheme

Here you will learn the basics, how to use keccak256.

pragma solidity ^0.8.13;

contract HashFunc {
    function hash(
        string memory _text,
        uint _num,
        address _addr
    ) external pure returns (bytes32) {
        return keccak256(abi.encodePacked(_text, _num, _addr));
    }

    function getHash(address _addr, uint _num) external pure returns (bytes32) {
        return keccak256(abi.encodePacked(_addr, _num));
    }
}