Solidity – How to Create Array of Multiple Data Types

contract-designcontract-developmentsoliditytruffle-contractweb3js

Since struct cannot be output from solidity to web3js,
I'm using arrays, I could get single datatype array in the below code(userAddress), but I'm not able to take multiple value in array(userName,userTarget).Any suggestions howto would be great

Solidity:

struct Person
    {
        address userAddress;
        string userName;
        uint userTarget;
    }
     mapping (uint => person) Persons;
     uint[] public personAccounts;
     uint incr = 0;

     function setDetailse(string  data, uint target) public
    {
        uint icr = incr++;
        address _address = msg.sender;
        var person = persons[icr];

        person .userAddress = _address;
        person .userName= _vote;
        person .userTarget = target;
        person Accounts.push(icr) -1;
    }

   function getPerson() view public returns(uint[])
   {
       uint256[] memory data =  new uint256[](11);
       for(uint i = 1; i<=10 ;i++)
        {
           data[i]=personAccounts[i];
        }
       return data;
   }

web3js:

GetDetails: function(Data, account) {
  event.preventDefault();
  var dataInstance;

  web3.eth.getAccounts(function(error, accounts) {
    if (error) {
      console.log(error);
    }

    var account = accounts[0];

    App.contracts.Details.deployed().then(function(instance) {
      dataInstance= instance;
      return dataInstance.getPerson();
    }).thenfunction((numbers => {
      const [ nums ] = numbers;
      for (var i = 0; i <nums.length; i++) 
    {
          console.log("address: "+nums[i]);
      }
  })).catch(function(err) {
      console.log("error executed");
    });
  });

Best Answer

One can not create an array of multiple data types. An array must contain elements of the same data type. As one can not return a struct from solidity function you cannot use an array of struct. Refer this question for how to return multiple data types from a solidity function.

Related Solutions

Solidity – Query Multiple Smart Contracts’ Public Data

This is a hub & spoke pattern adapted to roughly map to your code. The Hub deploys Person contracts and keeps track of them. You can iterate over the unordered list from web3 and delete an item from the list if needed. You can add or remove person and hub privileges at the person level. For example, if you want, you can have a selfDestruct function in the Person contract and make it onlyOwner (only Hub can destroy it) or onlyPerson for self-delete. Presented without warranty. Very little testing. ;-)

pragma solidity ^0.4.6;

contract Hub {

  // two-way interable index with delete
  mapping(address => uint) personMap;
  address[] public personIndex;

  address public owner;

  function Hub() {
    owner = msg.sender;
  }

  modifier onlyOwner() {
    if(msg.sender != owner) throw;
    _;
  }

  function createPerson() 
    public
    returns(address newPerson)
  {
    Person p = new Person(msg.sender);              // whoever called this will "own" the Person contract created
    personMap[p] = personIndex.length;              // remember where it lives in the unordered list
    personIndex.push(p);                            // append to the end of the list
    return p;
  }

  function deletePerson(address person) 
    onlyOwner
    returns(bool success)
  {
    // step by step for clarity
    uint location = personMap[person];              // location on the list
    address personAddress = personIndex[location];  // should match the person
    // as one line
    if(personIndex[personMap[person]] != person) throw; // non-existent person
    // move the last item in the index to the location where the unperson was
    personIndex[personMap[person]] = personIndex[personIndex.length-1];
    // also have to update the personMap because the last item changed position in the list
    // whoever was in the last row is now in the row where we are removing a record
    personMap[personIndex[personIndex.length-1]] = personMap[person]; 
    // now the list is shorter
    personIndex.length--;
    // person is removed from the list
    return true;
  }

  // the next two functions make the unordered list of contracts iterable

  function getPersonCount() 
    public
    constant
    returns(uint count)
  {
    return personIndex.length;
  }

  function getPersonAtIndex(uint index)
    public
    constant
    returns(address person)
  {
    return personIndex[index];
  }
}

contract Person {

  // address public owner;
  address public personOwner;

  struct PersonStruct {
    bytes32 encrypted1;
    bytes32 encrypted2;
  }

  PersonStruct p;

  modifier onlyPerson {                       // add this to functions only the "person" passed in should be able to do
    if(msg.sender != personOwner) throw;
    _;
  }

  function Person(address person) {
    personOwner = person;                   // passed in by the creating Hub
    // owner = msg.sender                   // this would enable the Hub to have certain privileges if needed
  }

  function getPerson()
    onlyPerson
    constant
    returns(bytes32, bytes32)
  {
    return(p.encrypted1, p.encrypted2);
  }

  function setPerson(bytes32 part1, bytes32 part2)
    onlyPerson
    returns(bool success)
  {
    p.encrypted1 = part1;
    p.encrypted2 = part2;
    return true;
  }
}

Go-Ethereum – Uncaught Error: new BigNumber() Not a Base 16 Number

Base 16 is hexadecimal. The variable iPos you're giving to getFirstname is base 10 IE "0"

Hexademical is 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F <-- Sixteen positions.

Demical is 0,1,2,3,4,5,6,7,8,9 <-- Ten positions.

The number zero in Base 16 is 0x0.

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