语用中的预期主表达式错误^0.8.0

Question

我试图从下面的链接中使用任何uint来字符串函数实现。

如何将uint转换为字符串？

如何将字符串转换为int

将uint转换为字符串

然而，在务实的solidity ^0.8.0中，编译器显示了以下错误：

ParserError:预期的主表达式.

有解决办法吗？

例如，此实现会产生该错误。

function uintToString(uint v) public returns (string memory) {
    uint maxlength = 100;
    bytes memory reversed = new bytes(maxlength);
    uint i = 0;
    while (v != 0) {
        uint remainder = v % 10;
        v = v / 10;
        reversed[i++] = byte(48 + remainder);
    }
    bytes memory s = new bytes(i); // i + 1 is inefficient
    for (uint j = 0; j < i; j++) {
        s[j] = reversed[i - j - 1]; // to avoid the off-by-one error
    }
    string memory str = string(s);  // memory isn't implicitly convertible to storage
    return str;
}

Answer 1

不能直接将uint256转换为bytes1，但如果首先将其转换为uint8，则可以：

reversed[i++] = bytes1(uint8(48 + remainder));

完整的代码如下所示：

function uintToString(uint v) public pure returns (string memory) {
    uint maxlength = 100;
    bytes memory reversed = new bytes(maxlength);
    uint i = 0;
    while (v != 0) {
        uint remainder = v % 10;
        v = v / 10;
        reversed[i++] = bytes1(uint8(48 + remainder));
    }
    bytes memory s = new bytes(i); // i + 1 is inefficient
    for (uint j = 0; j < i; j++) {
        s[j] = reversed[i - j - 1]; // to avoid the off-by-one error
    }
    string memory str = string(s);  // memory isn't implicitly convertible to storage
    return str;
}