Questions tagged [blockchain]
The Ethereum blockchain is a distributed database based on the Ethereum whitepaper specification and stores both the full transaction list and the most recent state.
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NFT (Rarible) double item
I’m new in NFT and Rarible as NFT sell point.
I have enter one of my images to sell, but after 2 days of pending signing contract in my Coinbase Wallet, I received message “failed“.
I have started ...
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Total supply of deployed token is wrong
I made a BEP-20 (ERC-20) Token.
Can you guys suggest me what mistake i did. I am getting total supply 0.001 MKY. It should be 1000000.
contract Token {
/// @return total amount of tokens
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Server knows that a message is coming from owner of a token?
So I am trying to understand ethereum better, am an amateur. So excuse my naivete here. I am trying to think through this scenario to know if its possible, or how it could be implemented. If any of ...
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How to kill a contract in ethereum?
I'm trying to kill this contract
/**
*Submitted for verification at Etherscan.io on 2016-08-31
*/
//sol Wallet
// Multi-sig, daily-limited account proxy/wallet.
// @authors:
// Gav Wood <g@...
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Is it possible to know which will get the next pending block?
Is it possible to predict which miner will mine the next pending block on ethereum mainnet?
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Recommended approach to becoming a developer in the space
Like a lot of people I’ve following the space closely for about 3 and a half years now (admittedly as a speculator) and am keen to get deeper into contributing to the space as a developer.
I have been ...
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Ethereum blockchain size growing forever
I have been wondering what is the future of ethereum (or any other blockchain) if the blockchain just keep growing and growing, at some point its size will be so huge that only very few nodes in the ...
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Calling a function from another contract is not working. But calling the function from deployed contract is working
I have a problem with calling a function from another contract.
I don't know why it is not working.
Contract DateTime(https://github.com/pipermerriam/ethereum-datetime) is a util for converting ...
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Synchronous call of external contract function in Solidity
I have two Solidity contracts, where contract Caller depends on a second contract Callee. Contract Callee provides a public view function which checks the validity of a string (e.g. an password), ...
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THETA token sent to contract address instead of correct wallet address
By mistake, I sent my THETA token to the contract address instead of my correct wallet address.
This is the transaction link on Etherscan https://etherscan.io/tx/...
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Is Merkle tree applicable at block level also?
As per my understanding, Merkle tree is applied in case of transactions. Through Merkle tree we generate root hash transaction from all the transaction present in a block. So does it work the same way ...
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What is an Ethereum address
How do I find my particular ethereum address and is it safe to give out? I need a very simplified version of how all this works. The research I’ve encountered so far is not helpful because I’m not a ...
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The value of my variable change
I have two contracts (A and B) in the same smart contract. When I access from B to a A's variable the value is different that I can see from A.
For instance, when I access from A to that variable ...
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Solidity finds eth price but its realy big
This script gives me some random like a number and not real eth price? the price that is outputting is 38598000000?!
AggregatorInterface internal ref;
// For ETH-USD on ropsten, input the address:
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Would it be possible to loan a cryptocurrency and get interest?
Would it be possible (future) to loan a blockchain (crypto) and get interest? (Like bank would lend money to user who needs it and gives interest to who invest?)
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How can i tell if geth is done running?
Well i am new trying to mine and i did the "C:>geth --rpc" and its still going how will i know when its done? i did all the steps leading to this but my pc just keeps running the
INFO [05-18|23:32:...
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Test not working in truffle
Got his error when run truffle test
Using network 'test'.
Compiling your contracts...
===========================
> Compiling .\test\TestFirst.sol
> Compilation warnings encountered:
/D/...
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Block Reward vs Block Time
I don’t understand how is it possible that every 15 seconds (block time) 2 ETH are created but it takes 62.8 days to mine 1 ETH and 125.6 days to solve 1 block mining solo. Where can I find more ...
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Will a transaction that depends on another transaction be included in the same block by a miner?
Consider two transactions, A and B. A is valid given the state of the blockchain as of the last block. B is currently invalid, but becomes valid once A takes effect. A and B are from the same caller ...
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Is ganache decentralised?
According to Dapp the blockchain should distributed, But while we use ganache it runs on a local machine and the clients will be having only their private key and public key (or wallet) with them ...
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Is ethereum transaction fee supposed to be proportional to the amount sent
I am using the blockchain.info iOS wallet. I am trying to send a small amount of ETH. However, the fee “suggested” by the wallet is a whopping 0.003234 (~ 6 USD). If I changed the amount of ETH i want ...
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If a block header is 80bytes, then why does a full node need ~100GB of storage
So, I'm a little confused about how data is stored in a block. If You can get the state of all accounts from the State Root of a block header, then that means that you can get the state of every ...
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How to calculate token buy and sell prices?
I have a ERC20 token
string public name = "Token ZIZ";
string public symbol = "ZIZ";
uint8 public decimals = 18;
uint256 public totalSupply = 1000000 * 10 ** uint256(decimals);
//...
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org.web3j.protocol.exceptions.ClientConnectionException: Invalid response received: okhttp3.internal.http.RealResponseBody
Environment
Android Studio
Infura – Rinkeby test network
Web3J
Metamask
Rinkeby.etherscan.io
I am trying to build an Android app to read and write smart contract by following the medium article:
...
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Zora doesn't allow NFT 1 of 1 editions? [closed]
Zora is decentralized marketplace for NFTs that doesn't take any fees from sales of NFTs, built on the Ethereum blockchain. Zora's help docs says
Instead of creating artificial scarcity by selling ...
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Which Ethereum user bought Beeple's "Crossroad" NFT video for $6.6 million?
we know the story of who bought Beeple's "Crossroad" NFT video for $67,000 and re-sold it on the secondary market for $6.6M worth of ETH, but who exactly was the person, or Ethereum username,...
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Do Data and Nonce both play a role in hash?
If a transaction's hash doesn't change with data it makes blockchain mutable.
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What's the difference between Binance ERC20 and Coinbase ERC20 ...?
As a newbie I made a mistake whilst transferring btc to from Binance and Coinbase. My mistake was I didn't check the receive address with Coinbase and it defaults to eth and I wanted to send btc to ...
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How many new nodes join the Ethereum Network per month? How many leave?
I'm researching the cost of serving old blocks to new nodes that need to synchronize and download the whole blockchain. I can indirectly estimate the bandwidth consumed to serve old blocks, if I know ...
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Can't compile old solidity contracts(version 0.4.17)
I'm new with blockchain development.
I'm working on an old project which use solidity 0.4.17 and truffle ^4.0.0-beta.2;
These versions were in the package.json file of the project.
When I installed ...
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From what source does etherscan.io aggregate and broadcast data that appears on the blockchain ledger?
as blocks are hashed together as transactions pile up and are broadcasted on the Ethereum blockchain, how exactly does the website etherscan.io in turn publish and broadcast all that information in ...
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Can we mint 5 gigabyte video NFTs?
What is the maximum size of NFTs on the Ethereum blockchain (ERC-721 or ERC-1155 tokens)?
crypto art NFTs on the Ethereum blockchain already contain JPG/PNG files that are about 5 MB large, and ...
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Can I use conversation messages stored on Blockchain
I'm new to Blockchain and exploring if I can safely store textual and media content in the transaction. This will help me with the following outcomes
I can have a safe, secure storage of contents ...
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how to call a function of a smart contract from a c program using JSON-RPC
Indeed, i installed ganache where i deployed a smart contract.
I wanted to write a c program that would allow me to call the functions of my smart contract and read the messages.
This program would ...
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Learning go-ethereum For Custom Chain
Is there a site to find out all about source code go-ethereum? I want to learn fully about the Ethereum blockchain.I want to learn private blockchain to learn more.
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transactions are performed sequentially by the blockchain, but how are the waiting times managed?
I have a booking dapp where you can make reservations and call the bookRequest method. If many users call this method, it is not possible to know the order in which they will be performed and ...
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how to create a smart contract that uses ERC20 as way of payment?
im creating a smart contract that will receive and automatically redistribute erc20 tokens!
how can i implement that in solidity?
i've tried a couple of codes examples but nothing have worked so far!
...
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How does a node execute the smart contract in the EVM and update the blockchain with result of contract execution
I would like to understand how the Ethereum Node is loading the contract bytecode in the EVM and then write everything that it needs, back to the blockchain.
This is how I understand it.
The contract ...
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Parse the whole blockchain
I want to parse the whole blockchain(I know it might sound a bit too much). I have installed both solidity and geth.
My idea was to get the current block that is being mined, essentially the current ...
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Please help with Parsing Expected ',' but got ';'
I have looked far and wide for a solution and have read solidity documentation. Please help me find the parsing error in the code.
Thanks in advance.
var KiwiCoinSale = artifacts.require('KiwiCoinSale'...
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API for circulating supply
I am trying to list circulating supply on coingecko for an ERC20 token - how would I go about doing this? I've been able to find one for total supply, but not circulating however.
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Using Phoenix Miner - Noob Question
I am using Phoenix Miner - Ran it for around 8 to 10 hours as a trial - I setup my Public Wallet ID as My wallet ID, I have yet to see anything pending into my account - I am wondering If I am missing ...
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Invalid implicit conversion from rational_const 5 / 2 to uint256 requested
I have the following code snippet inside my contract:
plans[1100] = Plan(7, 3);
plans[1101] = Plan(7, 2.5);
plans[1102] = Plan(15, 4);
plans[1103] = Plan(30, 6);
plans[1104] = Plan(30, 5);
When I try ...
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Problem with old Xeth wallet syncing up
I've got some ETH on an old XETH wallet from 5 years or so and I've never been able to retrieve it. The ETH doesn't show up in the wallet and the sync bar is completely blank. Based on another ...
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Is Ethereum a decentralized or distributed blockchain?
Is Ethereum a decentralized or distributed blockchain? I read the documentation but I can't understand.
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How to write a smart contract for access level (read/write)?
I have seen a couple of tutorials on how to code smart contracts, but I can not quite gather how to write one for permission and access level on a blockchain. How can you grant access to a user to ...
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How to call a function with ethereum alarm clock?
In Ethereum alarm clock who is calling the contract (scheduler?) that executes the function programmed in my contract. I mean, I have a function in my contract that needs to run on a certain date, but ...
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what are the technological limits of a smart contract?
I know that:
a smart contract cannot initiate any type of transaction but needs an external trigger. Each transaction is triggered by an EOA
Smart contracts cannot subscribe to events or access them ...
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Get balance in fast node by Geth
Is it possible to get account Balance in fast node with Geth ?
and what is the size of fast node currently?
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Can my backend call a smart contract function to be executed on a certain date?
The architecture of my dapp consists of a backend (metamask + web3.js or web3.js + geth) and a smart contract that offers different services (functions). I want a function on the smart contract to run ...
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