Trying to convert address string to type address in Solidity

user_1619003 0
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I am trying to convert address string to type address in solidity but when I am doing

    function StringToBytes(string memory _str) public pure returns (bytes memory) {
        return bytes(_str);
        
    }
    function StringToBytesLength(string memory _str) public pure returns (uint256) {
        return bytes(_str).length;
        
    }

The result of StringToBytes is giving me 42 which should ideally gives me 20. If I am trying the same thing in python i.e convert string to bytes , it is giving me 20 bytes which is the length of an ethereum address in bytes. I had found several solutions to convert address string to address type but none of them is working for solidity version 0.7. Please help.

solidity ethereum
1 Answers

I want a solution but it is not optimal, I am looking for a solution which is lighter on gas fees, It is now consuming 77492.


    function fromHexChar(uint8 c) public pure returns (uint8) {
        if (bytes1(c) >= bytes1('0') && bytes1(c) <= bytes1('9')) {
            return c - uint8(bytes1('0'));
        }
        if (bytes1(c) >= bytes1('a') && bytes1(c) <= bytes1('f')) {
            return 10 + c - uint8(bytes1('a'));
        }
        if (bytes1(c) >= bytes1('A') && bytes1(c) <= bytes1('F')) {
            return 10 + c - uint8(bytes1('A'));
        }
        return 0;
    }
    
    function hexStringToAddress(string calldata s) public pure returns (bytes memory) {
        bytes memory ss = bytes(s);
        require(ss.length%2 == 0); // length must be even
        bytes memory r = new bytes(ss.length/2);
        for (uint i=0; i<ss.length/2; ++i) {
            r[i] = bytes1(fromHexChar(uint8(ss[2*i])) * 16 +
                        fromHexChar(uint8(ss[2*i+1])));
        }

        return r;

    }
    
    function toAddress(string calldata s) public pure returns (address) {
        bytes memory _bytes = hexStringToAddress(s);
        require(_bytes.length >= 1 + 20, "toAddress_outOfBounds");
        address tempAddress;

        assembly {
            tempAddress := div(mload(add(add(_bytes, 0x20), 1)), 0x1000000000000000000000000)
        }

        return tempAddress;
    }
user_16190030
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