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1500 questions
12
votes
1 answer

Is it possible to have mappings inside mappings?

Is this possible? mapping(address => mapping(uint => customStruct[])) someName Because I cannot debug and find my mistake... is there not enough gas, or it crashes on this code, while trying to fill someName. For example: uint length =…
mrAkax
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12
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1 answer

Peer discovery not working on private network

I'm running 3 nodes with the following command: geth --verbosity 4 --autodag --nat any --genesis /opt/blockchain/genesis.json \ --datadir /opt/blockchain/data --networkid 4828 --port 30303 --rpc \ --rpcaddr 10.48.247.25 --rpcport 8545…
Henrique Barcelos
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12
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2 answers

Can someone explain 'signing a transaction' and how its different from sending ether?

Some times when using meta mask or other contracts, instead of sending an amount, I simply sign the transaction. see here Say I want a function() that renames a string. function string(string name){ string myname = name; } How would I make…
Zach
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12
votes
4 answers

web3 js php implementation

Is there any way to communicate with ethereum through php ? what i want is to get Smart contract details from contract address like Contract token name, decimal, abi, balance, tokens supply symbols etc. till now what i know is web3.js is a official…
Talha Malik
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12
votes
1 answer

Why is the Ethereum paper called the "yellow paper"?

I googled this and this does not exist here yet, so Why is the Ethereum paper called the "yellow paper"?
JohnAllen
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12
votes
1 answer

Looking for a working Whisper example

I was looking to develop an application using Whisper & NodeJS and I'm having trouble finding an example that works and is updated. I've encountered this doc web3js.readthedocs.io/en/1.0/web3-shh.html and this guide…
Tiago Loriato Simões
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12
votes
2 answers

Is there a formal specification for the EVM?

The yellowpaper specifies the EVM, albeit in a fashion that favors formalism over readability: But there's no indication if this is up to date with the current state of the Ethereum ecosystem or not, and I haven't been able to find a formal VM…
Nick Johnson
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12
votes
2 answers

Clarification of "256 bit word" semantics

EVM has "256bit words". Some cases treat strings shorter than 32 bytes (256 bits) as left-justified ascii (packed into the most significant bytes of the word). Does this mean that the word value of the string '*' is equivalent to: 42 << 148 ? Note…
rethsid
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12
votes
3 answers

Truffle & Web3 1.0.0-beta : does it work for anyone?

I'm trying to make the latest Truffle (3.4.3) and Web3 (1.0.0-beta11) to work together in a React app. It fails when I try to call myContractInstance.deployed() import { default as Eth} from 'web3-eth'; import { default as Contract } from…
szerte
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12
votes
3 answers

Convert contract arguments from JSON to ABI-encoded format

I want to verify a contract code on Etherscan, but don't know how to get the arguments in ABI-encoded format. I have the source code and the interface in JSON. Is there some tool I can use, or some easy way of getting the JSON to the ABI…
user15943
12
votes
4 answers

CryptoCurrency NODE.js Web3 Ethereum - Can't connect to TESTRPC

I am trying to connect to my testrpc instance from a my web3 application but I can't seem to connect. The below code should return an array of all the accounts in the testrpc chain. Code: Web3 = require('web3') web3 = new Web3(new…
Code
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12
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4 answers

Running truffle migrate just opens my truffle.js file and does nothing

I am following this tutorial: http://truffleframework.com/tutorials/building-dapps-for-quorum-private-enterprise-blockchains. I am trying to run truffle migrate on my project but it just opens my file in VSCode and nothing seems to happen. Any…
Evan
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12
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4 answers

How to deploy smart contract in predefined contract address in private ethereum network?

Is there any method to deploy our smart contract in a particular address (ie. predefined contract address) in private ethereum network? Yes, I have built my own private blockchain based on Ethereum code. I need to deploy contract on some blocks and…
Karthikeyan Thangavel
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12
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2 answers

How do I change the owner of an ENS domain using MyEtherWallet?

Does anyone know the exact procedure for doing this? It looks quite straightforward, but I'm unwilling to try it out without confirmation from someone who's done it already.
Name
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12
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3 answers

Best way to burn ethers and other ethereum tokens?

Is it correct that any ethers or tokens sent to the address 0x0000000000000000000000000000000000000000 will be destroyed? Or what is the best way of burning ethers / tokens?
Resten
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