Solidity

Question

我曾尝试使用编译器版本 0.5.12 编译此代码，但出现异常：

browser/Untitled.sol:21:24: DeclarationError: Identifier not found or not unique.

function getRoleOf(adress ad) public returns(string txt){

^----^

我的代码：

pragma solidity >=0.4.22 <0.5.13;
contract Max{
    mapping(address => uint256) private balaces;
    mapping(address => role) private roles;
    enum role{
        Admin,
        Manager,
        User
    }
    
    constructor() public{
        balaces[msg.sender] = 1000;
        roles[msg.sender] = role.Admin;
    }
    
    function getRoleOf(adress ad) public returns(string txt){
        if(roles[ad] == role.User){
            txt = "User";
            return;
        }
        if(roles[ad] == role.Manager){
            txt = "Manager";
            return;
        }
        if(roles[ad] == role.Admin){
            txt = "Admin";
            return;
        }
        return "Нет такого пользователя";
    }
}

我的代码有什么问题？

Answer 1

输入错误:function getRoleOf(adress ad) adress 应该是 address

以下使用 Solidity Compiler 0.4.26 在 Remix 中编译

pragma solidity >=0.4.22 <0.5.13;
contract Max{
    mapping(address => uint256) private balaces;
    mapping(address => role) private roles;
    enum role{
        Admin,
        Manager,
        User
    }

    constructor() public{
        balaces[msg.sender] = 1000;
        roles[msg.sender] = role.Admin;
    }

    function getRoleOf(address ad) public returns(string txt){
        if(roles[ad] == role.User){
            txt = "User";
            return;
        }
        if(roles[ad] == role.Manager){
            txt = "Manager";
            return;
        }
        if(roles[ad] == role.Admin){
            txt = "Admin";
            return;
        }
        return "Нет такого пользователя";
    }
}

Answer 2

以上答案（来自@abcoathup）适用于 0.4.26，如果您想在 solidity 版本 0.5.12 中执行代码，请检查以下代码（稍作优化）

pragma solidity >=0.4.22 <0.5.13;
contract Max{
    mapping(address => uint256) private balaces;
    mapping(address => role) private roles;
    enum role{
        Admin,
        Manager,
        User
    }

    constructor() public{
        balaces[msg.sender] = 1000;
        roles[msg.sender] = role.Admin;
    }

    function getRoleOf(address ad) public returns(string memory txt){
        txt = "Нет такого пользователя";
        if(roles[ad] == role.User){
            txt = "User";
        } else if(roles[ad] == role.Manager){
            txt = "Manager";
        } else if(roles[ad] == role.Admin){
            txt = "Admin";
        }
        return txt;
    }
}

Answer 3

pragma solidity ^0.8.0;

导入“https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/ERC20.sol”;

合约 BlackLivesMatterToken 是 ERC20 { 构造函数（unit256 initialSupply）public ERC20（“BlackLivesMatterToken”，“BLM”）{ _mint(msg.sender, initialSupply); } }

Answer 4

getRoleOf(adress ad) --> getRoleOf(address ad)

它的拼写错误address。

Solidity - Error: Identifier not found or not unique. Compilation error

Solidity - Error: Identifier not found or not unique. Compilation error

compilation