Questions tagged [ether]

Ether (ETH) is the main internal crypto-fuel of Ethereum and is used to pay transaction fees.

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How Does Exchanges Implement Gas Fees for ERC20 Tokens

Any crypto exchange like binance, bitfinex and so on let you deposit and withdraw various ERC20 tokens. Technically I don't understand how they implement gas fees when I withdraw? I deposited 100 ...
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1answer
66 views

How to update value on ethereum blockchain without metamask?

pragma solidity 0.4.24; contract UniToken{ string value="Hello"; function set(string x) public { value = x; } function get() public view returns (string) { return ...
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1answer
34 views

Multiple Array[] along with mapping handling

This code is running but when the same user make a bid then the bid is being replaced from the first bid and event is printing twice the same record. i want that one address make a bid and for his ...
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3answers
375 views

infura vs Eth Node [duplicate]

I want to connect web3 services with public Ethereum (main net/test net) to execute my smart contract method. Which is better Infura or to create my on Node? Please suggest.
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1answer
51 views

In proof of stake, is there a difference between being offline and deciding to leave entirely?

I'm struggling to understand the proof of stake concept. As I understand it, in order to participate in validation and its rewards, you must ante up some ether (I was told a minimum of 32). You are ...
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1answer
66 views

Solidity keyword require (false) will run out of my gas, why?

I meet a strange problem when I test my contract in Remix-ide + geth 1、I run a private chain in geth 2、I connect to the node with web3provider in Remix-ide 3、I deploy the contract like this : ...
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2answers
68 views

What is wrong with the 'sell' and 'buy' token functions in my contract? [closed]

There is my solidity function buyTokens(uint256 _numberOfTokens) public payable { // Require that value is equal require(msg.value == multiply(_numberOfTokens, tokenPrice)); // Require ...
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1answer
52 views

What are all possible values of txreceipt_status?

I was wondering what are all the txreceipt_status possible statuses. I was investigating some blocks and noticed that some statuses are empty like: ' ' or have '1'. For both of those, transactions ...
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1answer
44 views

What is the purpose of Private Blockchain?

What is the real purpose of private blockchain for example in Ethereum ? I mean found a lot of tutorials online about creating a private blockchain, creating an accounts there, setting coinbase accout,...
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1answer
184 views

The use of ERC20 tokens in a private ethereum network

I am being told to use a private blockchain instead of the public one in attempt to cut gas cost. But I was hit with the problem of the value of ether and tokens in this private blockchain. I am ...
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1answer
32 views

ICO and Token both together

I know we can create a token contract and also we can create a ico contract. Is it possible to create a contract include ICO and Token itself? any idea or example?
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2answers
73 views

DappHub Multiply Function

Could someone explain the use of performing a multiplication such as this? I mean the logic is fine, but what is the importance from a security point of view? function mul(uint x, uint y) internal ...
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1answer
27 views

What is a suitable pattern for mobile/web apps that leverage ether?

Looking to understand how to build an app that leverages Ethereum - what suitable patterns are out there (ideally to go via some tutorials). I'd like to build a Hello World simple app (mobile and/or ...
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1answer
79 views

Any option to get larger amount (i.e. 2000) of Rinkeby Ether?

We are planning to open our product to the public for live testing. We want to support both Ropsten and Rinkeby networks, just in case. When registering, each user should get around 10 ether on ...
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1answer
412 views

Remix is compiling the smart contract but not solc command

I am able to successfully compile a smart contract in remix IDE. However when I try to do the same with solc npm command, it shows a JSON error when compiling. Voting.sol pragma solidity ^0.4.25; ...
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2answers
39 views

What is meant by locking of ether in proof of stake?

In PoS, forgers stake their ether on a block. These ether are locked and can't be used. What does it mean by locking of ether and how does it work?
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1answer
95 views

the balance in genesis file is it in ether or wei?

In genesis.json file I have this balance : "bd7a14e103ffa97ec5fd96d9975adb1b52756ef3": { "balance": "0x200000000000000000000000000000000000000000000000000000000000000" } the hex number ...
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2answers
219 views

What are the use cases of tokens? How they are different than ethers?

I am searching for the ERC20. From what I found is that , tokens allow us to have our coins based on smart contracts. But I am little bit confused about the use cases of tokens? When I should use them ...
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0answers
41 views

Ethereum js wallet for php

https://github.com/ethereumjs/ethereumjs-wallet I need this library with the same functions in PHP Would u give me the link
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1answer
53 views

How to make fair gas consumption of smart contract users

i have made a contract that 2 users participate in the smart contract, both users do the same steps however i notice it that user1 pay more gas ( transaction gas and execution gas ) than user 2 any ...
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1answer
233 views

Smart Contracts without ETH Transactions

Maybe I'm wrong, but I understand that Smart Contract Transactions must always contain a "VALUE" field, that's to say, the amount of Ether Alice will transfer to Bob in case certain condition ...
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1answer
69 views

constructor should be payable if you want to use message sender

Hi There i was running this code on remix javascript vm. But this gave me error on buy function that constructor should be payable if you want to use message sender. I can't understand the mistake as ...
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2answers
178 views

I cannot send ETH from my blockchain wallet

Yesterday i have Transaction {Dropped & Replaced) https://etherscan.io/tx/0xfdca0e5c597f0a3f298afd5d56e939a8cefc10117df6b22d5342e1b6d5803caf I saw it Replaced by TxHash:...
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0answers
40 views

Is there a more elegant way to do an aggressive multi-send?

I understand there are many approaches to do multisend but for me timing is a priority and I do not want to stop the transaction if a address.send fails. function multiSend() internal isAdmin { ...
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2answers
92 views

How to dynamically load contracts data with their ABI from etherscan API?

Im wanting to pull data from a smart contract I've loaded via user address and etherscan API for the ABI. But how would I go about programmatically adding all the functions from the ABI into my ...
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1answer
113 views

Transaction dropped. How to increase gas fee?

I sent some ether using Ledger Live, but the gas fee was too low. Id like to increase the gas fee. I was told I can do this via Ledger Etherum Wallet for Chrome. However, when I open Ledger Etherum ...
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1answer
478 views

etherscan request API limit [closed]

i want to know the limit request on etherscan API with API key, and limit if we go on paid service. thanks in advance.
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1answer
101 views

Send eth from one account to another using transfer() function

I am trying to write a smart contract that will send eth from one account to another account : Contract Send { event Sent(address from, address to, uint amount ); function send(address _receiver,...
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2answers
45 views

Can I have someone submit my transaction to the network, so I don't have to pay the gas fee (in ether)?

My account is a new account with 0 ether. I just received 100 of ERC20 tokens. I would like to send these 100 tokens to the other account. However, since this account does not have any ether in it, so ...
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1answer
26 views

What is the max ethereum allowed in a private network for the whole network?

When I build a private chain setup, what is the maximum Geth ethereum I can have for the life of the network. Another way of asking the question would be: What is the maximum ethereum one account can ...
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2answers
32 views

Do I need to buy Eth for the transaction?

recently I've completed my transaction from empowr to ether wallet about 1003 empowr coin in total. But, the real problem is that the money doesn't show up in my wallet. But in etherscan it shows that ...
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0answers
70 views

Can we use Ethereum Swarm to store normal data other than blockchain or dapp data.

I want some basic data to be stored like name and city phone no etc.So just want to ask can I use ethereum swarm just to store file and make several node to create decentralized storage.
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2answers
55 views

How to call a function of a smart contract [closed]

I'm totally new to solidity I have a contract that I have to compile and deploy. Now, I have to interact with it (specifically with one of its functions) but I don't know how to do that and I feel ...
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1answer
152 views

Altering / overriding the method from main contract

I am using openzeppelin to create a ICO as a CappedCrowdsale and TimedCrowdsale as mentioned in the example mentioned in the below link. Reference : https://github.com/buddies2705/Solidity-Tutorial/...
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2answers
40 views

Sending hundreds of signed transactions with web3js which succeed but can only find a couple on Etherscan

I am using web3js to send hundreds of transactions to Ropsten (will eventually change to mainnet) and I am getting a tx hash for all of them, which means that supposedly, all the transactions have ...
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2answers
351 views

Truffle : dotenv is not working in truffle.js

I am trying to get the seed words from the powershell command prompt. Hence I am using the 'dotenv' in truffle.js require('dotenv').config(); console.log('aa - process.env.MNEMONIC : '+mnemonic); ...
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1answer
30 views

Is Ether just a naming convention?

I've been looking in the go-ethereum code (where it appears 24(!) times, mostly in comments) and around, I can't find any reference for Ether having any signification rather than a naming convention. ...
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1answer
130 views

how to watch the eth address with infura

our project now uses scheduled task to query the eth address with infura API to get its balance every 10 seconds but as the number of addresses keep increasing, the efficiency is very bad. Is there ...
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1answer
441 views

How to generate test funds for Infura Ropsten Network wallet

I have been using Web3.py, and Web3's TestRPCProvider to create some utility functions in Python to deploy a smart contract meant to generate an ERC20 Token, and then communicate with that smart ...
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1answer
286 views

Generate addresses using xpub

I have a cold storage where I installed BTC-Electrum and LTC-Electrum wallets. So I have took extended master public keys and have generating addresses in my online service. Now I want to generate ...
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1answer
44 views

I want to remove the timed aspect of this crowdsale contract and make it finalizable manually [closed]

Which lines do I remove and what do I replace them with to change this from a timed crowdsale contract into one I can end manually? pragma solidity ^0.4.18; interface token { function transfer(...
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1answer
87 views

Reading of state variables vs the memory varables . and memory vs storage keywords

contract Shopping { struct Article { uint id; address seller; address buyer; string name; string description; uint256 price; } // state ...
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1answer
29 views

Why my tokens aren't visible to the address sent in etherscan?

I've flattened the code and fixed the warning. But the problem with the contract is that the tokens are not visible in the addresses when searched with etherscan but when I try to add through Metamask,...
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2answers
95 views

Why it's showing errors in this contract?

Actually, I wrote the code in multiple files, but since I need to Verify and Publish the code so, I tried to flatten the code. But now it is showing way too many errors. I put the code below with ...
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1answer
39 views

how can I pair my ERC20 token with Ethereum

I am building an exchange and i just want to know how this pairing thing works. How can I pair my ERC20 token with other crypto assets like Ether and BTC?
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1answer
35 views

Ethereum Private network for Production use case

When I should consider to use Ethereum Private network for Production use case? Can I dictate network difficulty rules and apply permission on such network. Regards Dev
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1answer
33 views

I am trying to add ether to one of my ethereum account using smart contract

function Execution (address _from, address _to) { _from.transfer(price); _to.getBalance(_to) += price; } 1) I think it is duplicate but i gone through but nothing helped 2) I ...
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2answers
70 views

can't use the crypto money I earn working for gitcoin.com

Recently I resolved a public GitHub issue and was paid 125 units. I was told its worth about 125 dollars. I've installed the chrome metamask plugin. I also purchased 5 dollars worth of ETH from ...
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0answers
63 views

Triggering contract fallback function by sending ether from another contract

contract A { uint public u; event abc(address); constructor() payable{ u=100; } function () payable{ emit abc(msg.sender); u = 25; } function setu(uint i) { u = i; } function ...
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1answer
50 views

Estimation of gas in web3js 0.20

Q:- While sending only Ether One wallet to another wallet(NO SMART CONTRACT), do we need to define the default gas limit and price? i.e. 21000 * 3 OR 21000 * 4 OR 21000 * 5 etc Or I've need to use ...