All Questions

0
votes
2answers
23 views

Will 'x.send(amount)' revert if 'x' is a contract with a fallback function which reverts?

I know that x.transfer(amount) reverts if either one of the following two scenarios takes place: There is not enough ether in the calling contract, i.e., amount > address(this).balance Variable x ...
0
votes
1answer
16 views

Changing “proxywallet” in “local.config” in ethOS, but I receive mining reward in previous address

I've changed my proxywallet from proxywallet 0xB4... to proxywallet 0x5B... in the local.config file. However, I received mining reward again in previous address: 0xB4... . Do I need to restart the ...
0
votes
0answers
24 views

Check if a struct is empty

I have a function where I pass a id. With that id the contract find in a mapping a struct. My idea is to check if exists that struct with the given id with a if clause. I try with 0, null, "". Is ...
0
votes
1answer
17 views

Does MultiSig wallet's function follows any Token Standard i.e ERC223?

Does MultiSig wallet may include functions like increaseSupply, decreaseSupply and functionality like blackList addresses?
0
votes
1answer
23 views

Truffle will not compile contract written in VS code. Pragma error

I'm trying to run example from https://truffleframework.com/tutorials/pet-shop, but when I run truffle compile I get error saying Error parsing C:/WINDOWS/system32/TruffleTest/pet-shop-tutorial/...
0
votes
1answer
25 views

How to change the account that is interacting with the deployed smart contract on Ganache? [duplicate]

When I enter truffle console and start interacting with the deployed contract truffle uses the first address, how to change the address for testing ? user@user:~/workspace/smart-contract$ truffle ...
0
votes
1answer
6 views

Remix IDE : Passing array of address and array of uint

Working on the remix IDE, i cant seem to pass an array of addresses along with an array of uint as parameter to a function. It runs just fine on ethfiddle though and behaves exactly how i expected it ...
0
votes
2answers
29 views

Use private ethereum blockchain for storing data [on hold]

I am new in ethereum blockchain technologies. I have some question that Is possible to use ethereum blockchain to store data (Like MySQL)..??? If yes... (for first question) have any documentation ...
0
votes
0answers
29 views

UnhandledPromiseRejectionWarning: Error: “gas” is missing

How can I catch exception thrown by method call? (async () => { try { const contract = await MyContract.deployed(); const gasPrice = await web3.eth.getGasPrice(); contract....
0
votes
1answer
21 views

How to cast address to address payable in solidity 0.5.0

Got address from 3rd-party library: address wallet = rlp[5].toAddress(); And wanna transfer some funds to it: wallet.transfer(amount); Got error: TypeError: Member "transfer" not found or not ...
0
votes
1answer
34 views

Upgrading to solidity version 0.5.0 getting deployment failed error with same smartcontract perfectly deployed on 0.4.24

The same smart contract is running smoothly in solidity version 0.4.24 but now when I update the solidity version and solving a lot of bugs inside my smart contract I intended to deploy that in ...
0
votes
1answer
21 views

How to configure APIs to run with Ropsten addresses

I have my contracts deployed on Ropsten network. I deployed those contracts from my local machine using Truffle migrate. Then I set up an AWS EC2 Ubuntu server to host my RESTful APIs. I installed ...
0
votes
0answers
15 views

Why the same contract has more bytecode size in solidity 0.5 in compare to 0.4.24?

My earlier contract was compatible with solc@0.4.24. Now I am upgrading my contract to make it compatible with solidity 0.5 but it leads to an increase in bytecode size. AFAICT There is no change in ...
0
votes
1answer
14 views

Error in external function parameter defination for an interface

Dear community members, I have come across an error while defining an interface (just using the standard one interface ERC721TokenReceiver) this interface is mentioned in this link https://github....
0
votes
1answer
16 views

How to add actual Ether to custom token

I built a token by creating a smart contract for it, and have successfully connected to it, which is on a Ethereum test-net. Using web3.js I have been able to send token from one account to another ...
2
votes
0answers
19 views

Using web3.js, how can I get a TX hash before sending?

I'm using web3.eth.accounts.signTransaction() to obtain a rawTransaction, but I also need the transaction hash. calling web3.eth.sendSignedTransaction() will give me the hash, but I need to get it ...
3
votes
1answer
24 views

Why was the Constantinople hard fork postponed?

The Constantinople hard fork — really a network upgrade — was scheduled to happen today (January 16) at block 7,800,000. Instead the upgrade was postponed. What are the technical reasons for the ...
0
votes
0answers
17 views

Web3.js in Docker: invalid JSON-RPC response: undefined

Recently I've made a container out of my app, which used to work fine in a normal environment with an infura node. This is the code that's causing problems inside of the Docker container. I'm new to ...
3
votes
1answer
76 views

Will the Constantinopole hard fork create new coins?

Is the ethereum constantinopole hard fork going to result in extra forked coins for ethereum holders?
0
votes
1answer
20 views

Design Dapp with Kotlin front end

To develop Dapp using Kotlin programming language for the front end design, Where should I place this code? and what it should be changed? <script> // Connect a the web3 provider ...
0
votes
1answer
25 views

Contract deployment using web3.eth.contract(abi) with constructor arguments

I'm trying to deploy the following smart contract: pragma solidity ^0.5.00; contract TestContract { address public owner; string public word; constructor(string memory _word) public{ ...
2
votes
3answers
47 views

accepting ether in a smart contract

I want to create a simple smart contract for registration of users to a competition where when users can pay to contract and 2 ethers will deduct from his account. But when I'm trying to do so on my ...
0
votes
0answers
15 views

Truffle-contract cannot find module 'debug'

I'm trying to connect my smart contracts to a frontend app using web3 and the truffle-contract node package. In my client-side javascript file, I am requiring the package as follows: import contract ...
-1
votes
2answers
14 views

Expected import directive or contract definition… going crazy. same code different result [closed]

i am learning from a video course but the teacher doesnt have got the error i got. so we have the same code but different result (error on mine and all ok on his) here my code. pragma solidity ^0....
0
votes
1answer
35 views

Error CUDA mining: an illegal memory access was encountered

While mining after a while i got this error message "Error CUDA mining: an illegal memory access was encountered" or "Runtime error - ethash_cuda_miner::search, line 365" the miner works for some ...
0
votes
0answers
9 views

How to use web3.bzz with PoA network?

I'm trying to use web3.bzz with a poa network but I always get this error : invalid content type, only application/json is supported this the code: const file = fs.readFileSync("file.json"); web3....
0
votes
0answers
26 views

How to prevent DDOS in ethereum using PoA?

Using clique, how to prevent DDOS attack? Is there a way to set a whitelist of nodes which can send transactions, and blacklist all the others?
1
vote
1answer
24 views

How can I call a function in deployed contract on Ropsten Testnet when I don't have ABI and source code?

For some testing I deployed several contracts on Ropsten Testnet using web3.py but now if I want to execute them or call any function from them, how can I do this? I don't have ABI as I did several ...
1
vote
1answer
22 views

ERC721 Default Implementation

I’m working on a card game. Right now it is really simple. There are orcs and cards. Both should be implemented as ERC 721. What would be the most natural way to make the orc an ERC-721 token? ...
0
votes
0answers
13 views

What consensus are advised for a consortium supply chain?

Multiple organisations wants to share data around their supply chains systems What is the best consensus that is advised to use?
1
vote
0answers
13 views

Is Raiden viable for one way micro payments?

As an example if we wanted to increase participation on the Ethereum stackexchange, we could set up a contract to make micro payments out to stack members based on reputation/badges. This would only ...
0
votes
0answers
13 views

What is the role of the Geth ipc socket in a web3.js connection?

I started Geth as a root and try to run node.js with the rights of the group www-data. When node connects to Geth all is fine but transactions throw ... (node:27824) UnhandledPromiseRejectionWarning: ...
0
votes
0answers
11 views

How to generate Ethereum accounts using Web3 Python on Ropsten?

Just wanted to know how to use web3.py to generate Ethereum accounts. I tried using ropsten.infura.io/v3/<KEY> as an HTTPProvider, but it does not allows to create me account
0
votes
0answers
22 views

Matching inside my contract fails with multiple participants

my contract (can be found on my gist: https://gist.github.com/fabs993/e13fa6ecd9526d30c8a6d85c10180075) fails at more than 5+ participants. So in my use-case I have two kind of participants Producer ...
1
vote
1answer
34 views

How to call contract functions using web3?

I have deployed my contract in private blockchain, now I am calling functions using Nodejs and web3. Here, I want to transfer tokens for which I need to unlock my account from which I am transferring ...
0
votes
0answers
18 views

How do I collect addresses submitted by users for an ERC20 token airdrop? [on hold]

I'm planning on conducting an airdrop for 30,000 to 50,000 people, the site is ready, the executive summary, the whitepaper, the budget is set and the only thing i need to know is how to save the ...
0
votes
1answer
12 views

Stress test DApps on rinkeby test network

Is there any way of stress testing a dapp? I developed dapp, now I want to see how much stress it can handle? I can't test it on Main Ethereum Network. At least I can do it on Rinkeby test Network. ...
1
vote
0answers
31 views

Transactions from multiple addresses to a single address in Ethereum

We are currently in the process of developing a payment plugin for merchants to accept crypto payments. We are currently generating a unique order for every order which is placed in the merchant store....
0
votes
0answers
36 views

trying to verify and i can't make it, contract name is Mystatics and no matter what i try i get error please someone verify it for me or tell me how [closed]

cotract address 0xb5f8d22cdd53260d7f3401ebd9cc23ecfeb23409 token name: Mystatics symbol: MYST decimal: 18 TxHash:...
2
votes
1answer
26 views

How to integrate ERC 721 and 20 to create semi-fungible tokens?

ERC 721 defines non-fungible tokens where each token is unique. But if one needs to create a token where there is a limited supply of various types, is there a an effective way to accomplish this by ...
1
vote
0answers
24 views

How would you use a proxy erc20 contract if you cannot preserve msg.sender?

Let's say I use a proxy contract which allows me to make an ERC20 token transfer from my account. At the moment the only way to do so is to use tx.origin which gets the original EOA address of the ...
1
vote
1answer
17 views

Why wouldn't changing Difficulty variable help out in scaling?

I'm writing a thesis about smart contracts and one of my appraisers asked me to explain why changing the difficulty variable on the ethereum blockchain wouldn't help scaling. I know ethereum is ...
0
votes
0answers
21 views

How to get the return value of call methods in web3 v1? [closed]

As explained here, when we use web3 v1, we need to use a different way of calling functions (either to read the staet by call() or execute a function by sending transaction). It is not clear how we ...
0
votes
2answers
14 views

Optimization Exception Remix Editor

I am trying to compile my solidity code in remix editor. I keep getting this error "Optimization exception during compilation". I was using solidity version 0.5.2 till day before yesterday. Now, It is ...
0
votes
0answers
19 views

What is the current state of integrating sharding into ethereum? [closed]

I recently found articles about the topic 'sharding' and how it could help scale ethereum to make it faster in the end. Can anyone tell me what is the current state of integrating sharding into the ...
0
votes
1answer
16 views

Is geth account new and web3.eth.accounts.create the same?

For creating a new account, are these 2 commands the same or different? geth account new and web3.eth.accounts.create.
0
votes
0answers
13 views

I have a question about React-Native Bottom TebBar ..Help me please [closed]

I want to put an image that is not an icon in TabBar. So I wanted to put it in the TestMyCar Tab, and it didn't work. How can I apply it? This is the applicable App.Js code to apply. import React ...
0
votes
2answers
23 views

Call of contracts function reverted

Sorry for posting a block of code, but I just can't get this to work. I am using ganache for testing my contracts with mocha and NodeJS. Every time I call doTransfer, it fails. The call is reverted....
0
votes
0answers
19 views

Ethereum private Network for use case [closed]

I am new here, I have a question regarding decentralized applications. what should be used to connect different clients, like multi node ethereum private network over multiple pc. i found the ...
0
votes
2answers
26 views

Error generating new tokens in a private chain

pragma solidity ^0.4.25; // ERC20 Token Smart Contract contract MyToken { string public constant name = "MyToken"; string public constant symbol = "MYT"; uint8 public constant decimals = ...

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