Solidity 多行长字符串常量

Question

只是想知道是否有一种方法可以将长字符串拆分为多行？我找不到任何类型的行继续字符，如果您尝试使用这样的两行，则会抛出编译错误。连接字符串似乎也很复杂

 string memory s = "This is a very long line of text which I would like to split over
 several lines";

连接字符串似乎也很复杂。我只需要将很长的字符串放在很长的线上吗？

Answer 1

您可以将该值拆分为多个单独的字符串文字，每个字符串文字占一行。

pragma solidity ^0.8;

contract MyContract {
    string s = "This is a very "
        "long line of text "
        "which I would like to split "
        "over several lines";
}

文档：https ://docs.soliditylang.org/en/v0.8.6/types.html#string-literals-and-types

如果要连接多个字符串，可以使用abi.encodePacked()返回bytes数组的方法，然后将其转换bytes回string.

pragma solidity ^0.8;

contract MyContract {
    string s1 = "Lorem";
    string s2 = "ipsum";
    
    function foo() external view returns (string memory) {
        return string(abi.encodePacked(s1, " ", s2));
    }
}

编辑：从 v0.8.12 开始，您还可以使用string.concat()（以前版本中不可用）。

pragma solidity ^0.8.12;

contract MyContract {
    string s1 = "Lorem";
    string s2 = "ipsum";

    function foo() external view returns (string memory) {
        return string.concat(s1, " ", s2);
    }
}

文档：https://docs.soliditylang.org/en/v0.8.12/types.html#the-functions-bytes-concat-and-string-concat