# Solidity 学习笔记（一）

By [icona](https://paragraph.com/@happycity) · 2021-12-21

---

    pragma solidity ^0.4.19;
    
    import "./zombiefactory.sol";
    
    contract KittyInterface {
      function getKitty(uint256 _id) external view returns (
        bool isGestating,
        bool isReady,
        uint256 cooldownIndex,
        uint256 nextActionAt,
        uint256 siringWithId,
        uint256 birthTime,
        uint256 matronId,
        uint256 sireId,
        uint256 generation,
        uint256 genes
      );
    }
    
    contract ZombieFeeding is ZombieFactory {
    
      address ckAddress = 0x06012c8cf97BEaD5deAe237070F9587f8E7A266d;
      KittyInterface kittyContract = KittyInterface(ckAddress);
    
      // 这里修改函数定义
      function feedAndMultiply(uint _zombieId, uint _targetDna) public {
        require(msg.sender == zombieToOwner[_zombieId]);
        Zombie storage myZombie = zombies[_zombieId];
        _targetDna = _targetDna % dnaModulus;
        uint newDna = (myZombie.dna + _targetDna) / 2;
        // 这里增加一个 if 语句
        _createZombie("NoName", newDna);
      }
    
      function feedOnKitty(uint _zombieId, uint _kittyId) public {
        uint kittyDna;
        (,,,,,,,,,kittyDna) = kittyContract.getKitty(_kittyId);
        // 并修改函数调用
        feedAndMultiply(_zombieId, kittyDna);
      }
    
    }
    

zombieFactory.sol

    pragma solidity ^0.4.19;
    
    contract ZombieFactory {
    
        event NewZombie(uint zombieId, string name, uint dna);
    
        uint dnaDigits = 16;
        uint dnaModulus = 10 ** dnaDigits;
    
        struct Zombie {
            string name;
            uint dna;
        }
    
        Zombie[] public zombies;
    
        mapping (uint => address) public zombieToOwner;
        mapping (address => uint) ownerZombieCount;
    
        function _createZombie(string _name, uint _dna) internal {
            uint id = zombies.push(Zombie(_name, _dna)) - 1;
            zombieToOwner[id] = msg.sender;
            ownerZombieCount[msg.sender]++;
            NewZombie(id, _name, _dna);
        }
    
        function _generateRandomDna(string _str) private view returns (uint) {
            uint rand = uint(keccak256(_str));
            return rand % dnaModulus;
        }
    
        function createRandomZombie(string _name) public {
            require(ownerZombieCount[msg.sender] == 0);
            uint randDna = _generateRandomDna(_name);
            randDna = randDna - randDna % 100;
            _createZombie(_name, randDna);
        }
    
    }

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*Originally published on [icona](https://paragraph.com/@happycity/solidity-2)*