solidity 字符串拼接

solidity 字符串拼接

pragma solidity ^0.8.12;

contract StringDataType {
    string public s1 = "hello";
    string public s2 = "world";
    function combine() public view returns (string memory) {
        
        bytes memory s1b =  bytes(s1);
        bytes memory s2b =  bytes(s2);

        bytes memory result = new bytes(s1b.length + s2b.length);

        uint256 k = 0;
        for (uint256 i = 0; i < s1b.length; i++) {
            result[k++] = s1b[i];
        }
        
        for (uint256 i = 0; i < s2b.length; i++) {
            result[k++] = s2b[i];
        }

        return string(result);

    }

}