Stack Overflow
Stack Overflow

Questions tagged [ethereum]

Ethereum is a blockchain currency (like Bitcoin) with a public ledger. Questions should relate to programming. General questions about Ethereum should be asked on https://ethereum.stackexchange.com

is an open-source, public, blockchain-based distributed computing platform featuring smart contract (scripting) functionality. It provides a decentralized Turing-complete virtual machine, the Ethereum Virtual Machine (EVM), which can execute scripts using an international network of public nodes. Ethereum also provides a cryptocurrency token called , which can be transferred between accounts and used to compensate participant nodes for computations performed. Gas, an internal transaction pricing mechanism, is used to mitigate spam and allocate resources on the network.

was proposed in late 2013 by Vitalik Buterin, a cryptocurrency researcher and programmer.

The official website of is Ethereum.org

6757 questions
7
votes
1 answer

How sending transactions and receiving events work in backends in Ethereum blockchain

I am working on an ethereum project but I have some doubts. I have a backend that connects to the blockchain via web3.js. To connect to the blockchain I use a geth node. I understand that the sequence is this: send transacrion listen to events my…
EMANUEL
  • 103
  • 1
  • 5
7
votes
4 answers

Get Keys of Solidity mapping

I was trying to get keys of a mapping to star name and address of particular contract (not exactly) in solidity contract mapping(string=>address) nameOfAccounts; What i am expecting is a method like the Object.keys(nameOfAccounts) in Javascript. Is…
Mohamed Rashiq
  • 322
  • 1
  • 3
  • 12
7
votes
1 answer

Generate Ethereum addresses in HD Wallet using public key only (bitcoinj/web3j)

I trying to generate Ethereum addresses for the HD Wallet keys implemented with bitcoinj library, but I got confused: DeterministicSeed seed = new DeterministicSeed("some seed code here", null, "", 1409478661L); DeterministicKeyChain chain =…
Andrew
  • 179
  • 2
  • 9
7
votes
3 answers

Error: sending a transaction requires a signer while calling aggregate function of Multicall Contract Ethereum

index.js:1 Failed to fetch multicall chunk [{…}] 1 Error: sending a transaction requires a signer (operation="sendTransaction", code=UNSUPPORTED_OPERATION, version=contracts/5.0.2) Multicall contract address -…
Shanu Goyanka
  • 71
  • 1
  • 1
  • 2
7
votes
2 answers

'ENV' is not recognized as an internal or external command

So, I have been following tutorials of Eat The Blocks on ToDo List Ethereum DApp. Done till step 6, but while running the command npm run dev-front I am getting this error. > Project@1.0.0 dev-front L:\Project > ENV=development…
LinearMan
  • 89
  • 1
  • 1
  • 5
7
votes
4 answers

Sender account not recognized on private ethereum network

I'm currently developing a dApp in Solidity and am working on a web3 library to handle communication with it. I struggle with the process of new account creation and transaction signing in web3. Before I continue it worth noting that I'm running my…
Karim Stekelenburg
  • 633
  • 12
  • 26
7
votes
2 answers

How can I create a new account or address with web3.js?

I'm trying to interact with geth, and I need to create a new deposit address (and be able to control it). How can I implement this with web3.js?
Shamoon
  • 41,293
  • 91
  • 306
  • 570
7
votes
1 answer

Unable to attach to remote geth: Invalid pipe address '/.rinkeby/geth.ipc'

I'm on Windows trying to connect to Ethereum Testnet via rinkeby. I downloaded geth 1.8.2 and Ethereum Wallet 0.9.3 I gave 1st command as: geth --rinkeby --fast --cache=1024 NOTE: after above command, I get the url on cmd…
PrashantNagawade
  • 426
  • 1
  • 6
  • 24
7
votes
1 answer

How to make Observable from callback

I need to make observable from window.web3.eth.getCoinbase((error, result) => { ... }); Is it a good idea? new Observable(o => { this.w.eth.getCoinbase((err, result) => { o.next(result); o.complete(); }); });
Nazar Kalytiuk
  • 1,499
  • 1
  • 11
  • 21
7
votes
4 answers

Get token balance with Ethereum RPC?

how display balance of token through Ethereum RPC? $id = 0; $data = array(); $data['jsonrpc'] = '2.0'; $data['id'] = $id++; $data['method'] = 'eth_call'; $data['params'] = [['from' => '0x0...', 'to' => '0x0...', 'data' => 'contract byte code here…
avp
  • 666
  • 2
  • 7
  • 11
7
votes
1 answer

bytes32 to string in javascript

currently i'm working on a ethereum dapp(voting), in my smart contract i have a function to fetch candidate list of type bytes32[] , on the java script side i'm not getting the values instead 0x only How to parse the value , below is the…
Rahul
  • 462
  • 1
  • 4
  • 16
7
votes
2 answers

How to validate Ethereum addresses in PHP

I'm using PHP and curl with json to interact with my geth server. I'm able to do all I want except one thing: checking if user's inputted address is valid according to ethereum wallet format. I saw a javascript function here, but I'm mostly using…
btc4cash
  • 375
  • 1
  • 4
  • 15
7
votes
3 answers

What is the difference between creating a new solidity contract with and without the `new` keyword?

What is the use of the new keyword for creating new smart contracts? Why not just omit this keyword?
RFV
  • 831
  • 8
  • 22
7
votes
1 answer

How to call an Ethereum contract from Go?

I've tried to follow the go-ethereum guide for this but it seems out of date. I've tried looking around for a web3 library in Go but everything tries to point back to "use geth." From Go, how do I call a contract in the Ethereum block chain? How…
Corey Ogburn
  • 24,072
  • 31
  • 113
  • 188
7
votes
1 answer

Exact explanation of statistics displayed on https://ethstats.net

The site https://ethstats.net displays statistics about the Ethereum network but I did not find a precise definition of each statistic and graph displayed. Is there somewhere I can get this information?
Ajoy Bhatia
  • 603
  • 6
  • 30
1 2 3
…
99 100