I have bytes32 data which needs to be converted into a string, then use to get value from mapping(string => string)

Trying to convert bytes32 to string using : string(abi.encodePacked(temp))

It is working fine:

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Mapping contains key value pair : "har0 => "hello"


But when I uses the same string(converting from bytes32) in mapping to get the value, it doesn't gives value.

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1 Answer 1


You are trying to decode packed data, which is not possible with abi.decode. As abi.decode can only decode the data that's not packed.

The correct way to decode a bytes input is this

  function convert(bytes memory data) public pure returns (string memory) {
        return abi.decode(data,(string));

And to get the mapping:

function getmap(bytes memory key) public view returns (string memory) {
    return map[convert(key)];

try this and it will be working.

In case you really want to work with ancodePacked, you can look into some assembly code for this. Here is a relatable answer : How to decode `encodePacked` data

  • Please help me out ! Commented May 4, 2023 at 13:11
  • Did you try what I told you? It's working for me Commented May 5, 2023 at 12:58
  • yes, actually I have tried using with extra zeros at end like 0x68617230 rather than 0x686172300000.. 32 bytes total. It works fine. But I want to use bytes32 actually Commented May 6, 2023 at 16:21
  • Okay, it won't be possible because solidity doesn't have any function to decode packed data. Using assembly can solve your problem. Editing my answer with this update. Commented May 7, 2023 at 9:35
  • Updated the answer, please mark it as answer if it helped you. Commented May 7, 2023 at 9:39

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