We have a contract as follows:

pragma solidity 0.4.23; 

    contract RFID {

        struct StateStruct {
            bytes32 description;
            mapping(bytes32 => bytes32) sub_state;

        struct ObjectStruct {
            StateStruct state;
            address owner; 
            bool isObject;

        mapping(bytes32 => ObjectStruct) objectStructs;
        bytes32[] public objectList;
        //uint256 public number_of_sub_states = 3;

        event LogNewObject(address sender, bytes32 id, bytes32 sub_states_types, bytes32 sub_states_values, address owner);
        event LogChangeObjectState(address sender, bytes32 uid, bytes32 newState);
        event LogChangeObjectOwner(address sender, bytes32 uid, address newOwner);

        function isObject(bytes32 _id) public view returns(bool isIndeed) {
            return objectStructs[_id].isObject;

        function getObjectCount() public view returns(uint count) {
            return objectList.length;

        /*function setArraySize(uint256 _number_of_sub_states) public {

            number_of_sub_states = _number_of_sub_states;


        function getArraySize() view public returns (uint256) {
           return number_of_sub_states;

        function newObject(bytes32 _id, uint256 number_of_sub_states, bytes32[10] sub_states_types, bytes32[10] sub_states_values, address _owner) public returns(bool success) {

            uint256 counter=0;
            for(counter; counter < number_of_sub_states; counter++) {

                objectStructs[_id].state.sub_state[sub_states_types[counter]] = sub_states_values[counter];

                emit LogNewObject(msg.sender, _id, sub_states_types[counter], bytes32(sub_states_values[counter]), _owner);


            objectStructs[_id].owner = _owner;
            objectStructs[_id].isObject = true;


            return true;

        function changeObjectState(bytes32 _id, bytes32 _newState) public returns(bool success) {
            //objectStructs[_id].location = _newState;
            objectStructs[_id].state = StateStruct(_newState);
            emit LogChangeObjectState(msg.sender, _id, _newState);
            return true;

        function changeObjectOwner(bytes32 _uid, address _newOwner) public returns(bool success) {
            objectStructs[_uid].owner = _newOwner;
            emit LogChangeObjectOwner(msg.sender, _uid, _newOwner);
            return true;


When, I call function newObject in remix, I receive the following error:

Invoke newObject in remix using related text box : 100, 3, [bytes32("location"),bytes32("price"),bytes32("sold")], [bytes32("Paris"),bytes32("50"),bytes32("yes")], address(0xE07b6e5a2026CC916A4E2Beb03767ae0ED6af773)

ERROR : error encoding arguments syntax error unexpected token b in JSON at position 12.

What is the reason of this error ?

IMPORTANT NOTE : I edited my question regarding to the answer of user Jesse Busman.

2 Answers 2


I see four potential problems with your function call:

  1. You should use square brackets [] for array literals instead of curly braces {}:

    newObject(100, 3, ["location","price","sold"], ["Paris","50","yes"], '0xE07b6e5a2026CC916A4E2Beb03767ae0ED6af773');
  2. The newObject function takes dynamically sized arrays as arguments. From the Solidity documentation:

    Note that currently, fixed size memory arrays cannot be assigned to dynamically-sized memory arrays, i.e. the following is not possible:

    // This will not compile.
    pragma solidity ^0.4.0;
    contract C {
        function f() public {
            // The next line creates a type error because uint[3] memory
            // cannot be converted to uint[] memory.
            uint[] x = [uint(1), 3, 4];

    One solution is to change the function signature of newObject to accept only arrays of size 3:

    ..., uint256 number_of_sub_states, bytes32[3] sub_states_types, bytes32[3] sub_states_values, ...
  3. An array literal of strings cannot be implicitly converted to an array of bytes32. You can cast the values in the function call manually:

    newObject(100, 3, [bytes32("location"),bytes32("price"),bytes32("sold")], [bytes32("Paris"),bytes32("50"),bytes32("yes")], '0xE07b6e5a2026CC916A4E2Beb03767ae0ED6af773');
  4. Addresses in Solidity are written as hexadecimal constants casted to address. So you should write this: address(0xE07b6e5a2026CC916A4E2Beb03767ae0ED6af773)

    instead of this: '0xE07b6e5a2026CC916A4E2Beb03767ae0ED6af773'


I must invoke newObject function in remix in following format:

40,3,["location","price","sold","","","","","","",""],["Paris","50","No","","","","","","",""], 0xE07b6e5a2026CC916A4E2Beb03767ae0ED6af773

Now, the result is true.

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