如何修复Solidity编译器报错？uint256 public assetCount声明异常

我在编写FractionalRealEstate合约时，遇到了uint256 public assetCount相关的编译错误，尝试初始化该变量为0或1都无法解决。相关代码及错误信息如下：

合约代码 #

contract FractionalRealEstate {
    struct Asset {
        address owner;
        string description;
        uint256 totalShares;
        uint256 pricePerShare;
    }
    
    struct Order {
        address orderOwner;
        uint256 assetId;
        uint256 shareCount;
    }
    
    mapping(uint256 => Asset) public assets;
    mapping(uint256 => Order[]) public buyOrders;
    mapping(uint256 => Order[]) public sellOrders;
    uint256 public assetCount;

    ERC20 public token;
    address public owner;
    AggregatorV3Interface internal priceFeed; // Chainlink price feed contract
    

    constructor(address _tokenAddress, address _priceFeed) {
        token = ERC20(_tokenAddress);
        owner = msg.sender;
        priceFeed = AggregatorV3Interface(_priceFeed);
    }
    
    modifier onlyOwner() {
        require(msg.sender == owner, "Only contract owner can call this function.");
        _;
    }
    
    function registerAsset(string description, uint256 price, uint256 shares) external onlyOwner {
        require(shares > 0, "Shares must be greater than 0.");
        assetCount++;
        assets[assetCount] = Asset(msg.sender, description, price, shares);
        
        emit RegisterAsset(description, price, shares);
    }
}

编译错误信息 #

Compiling your contracts...
===========================
> Compiling ./contracts/FractionalRealEstate.sol

ParserError: 预期为函数、变量、结构体或修饰器声明。
  --> project:/contracts/FractionalRealEstate.sol:37:1:
   |
37 |     uint256 public assetCount;
   | ^

编译失败，请查看以上信息。
Truffle v5.9.2 (core: 5.9.2)
Node v18.16.0

解决方案 #

1. 清除特殊字符：错误根源是第37行存在不可见的特殊字符（如全角空格、非标准空白符），编译器无法正确解析。直接删除该行，手动重新输入uint256 public assetCount;，确保使用半角空格和标准语法。
2. 修正结构体赋值顺序：registerAsset函数中，Asset结构体的赋值参数顺序与定义不符。Asset定义的字段顺序是owner, description, totalShares, pricePerShare，需将赋值代码改为：

   assets[assetCount] = Asset(msg.sender, description, shares, price);
   

3. 补充事件定义：合约中调用了RegisterAsset事件但未声明，需在合约开头补充：

   event RegisterAsset(string description, uint256 pricePerShare, uint256 totalShares);
   

内容的提问来源于stack exchange，提问作者Gregory Betz