Solidity Function – Fixing Invalid Number of Arguments Error

truffleweb3js

I have tested it in remix and the function does work, I also removed inputs just for testing purposes but it seems that it doesn't work anyway.

Here is the function:

struct Message{
    string Message;
    int Vote;
    uint timeSubmit;
    bool isImportant;
    uint senderId;
}
Message[] messageArr; 
function getMessageString() public view returns(string memory){
        return messageArr[2].Message;
    }

I am calling it in web3.js like this:

  function getString() {
        messageInstance.getMessageString(function(error, result){
          if (error) {
              console.log(error)
          }
          else {
        console.log("yes")

      }})
    }

I am using truffle but it keeps giving me this error.

Best Answer

Function getMessageString takes 0 parameters, yet you are calling it with 1 parameter.

Therefore, change this:

messageInstance.getMessageString(function(error, result)

To something like this:

messageInstance.getMessageString().then(function(result)

Related Solutions

Solidity Function Argument Error – How to Fix Invalid Number of Arguments

Delete your build folder, then run the command. The reset command might work for some, didn't for me, might be a Mac thing. npm run truffle migrate --reset --compile-all I find it works best when running truffle locally to the folder rather than globally, due to the beta and different versions getting updated quickly recently. if you prefer the global approach try truffle migrate --reset --compile-all

solidity – Error: Invalid Number of Arguments to Solidity Function (Mapping)

Because you declared a public mapping, Solidity creates a getter. It looks something like this:

function myMapping(uint256 _index, uint256 _arrayIndex) 
    external
    view
    returns (uint256) 
{
    return myMapping[_index][_arrayIndex];
}

You mapping maps uint256's to uint256[] arrays. As Solidity's standard getter does not return arrays, you will have to specify which element in the array you want to the getter.

To get the first element of the first array in the mapping, use

myContract.deployed().then(function(instance) { 
    return instance.myMapping.call(0,0) 
});

If you want you smart contract to retrieve the array in full, try this function:

function myFullMapping(uint256 _index) 
    external
    view
    returns (uint256[]) 
{
    return myMapping[_index];
}

In JavaScript, you can use this code to get the first array in the mapping:

myContract.deployed().then(function(instance) { 
    return instance.myFullMapping.call(0) 
});

Best Answer

Related Solutions

Solidity Function Argument Error – How to Fix Invalid Number of Arguments

solidity – Error: Invalid Number of Arguments to Solidity Function (Mapping)

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