Linked Questions

143
votes
2answers
27k views

What is the difference between a transaction and a call?

What is the difference between a transaction and a call? In some interfaces, I can interact with contracts via calls or via transactions. What is the difference between the two, and can contracts also ...
85
votes
2answers
49k views

Which cryptographic hash function does Ethereum use?

Many sources refer to the use of the "SHA3" cryptographic hash function within Ethereum, but the Ethereum project began before the SHA3 standard was finalised, and there was some confusion/controversy ...
22
votes
2answers
15k views

How do I know how much gas to use when calling a contract?

When I am calling (sending a transaction to) a contract how do I determine how much gas to use? Is there a way to calculate this upfront & what happens if I send too much / too few gas?
13
votes
3answers
10k views

Is it possible to build a private (permissioned) blockchain with Ethereum?

Ethereum is a great blockchain, but for some services the transaction fee is prohibitively too expensive. Is there any project and/or guideline on making Ethereum so it works on permissioned ...
11
votes
2answers
702 views

Why does Ethereum have gas?

Why does Ethereum have gas? What other approaches could Ethereum have used to work around the Halting Problem?
8
votes
1answer
976 views

Can a transaction get lost?

Given that I am connected to the network with at least one peer, can I be sure that a transaction I sent will be executed (either with fail or success)? Is there a possibility that it will never make ...
7
votes
2answers
2k views

Who gets the fee from contract call?

Basically you don't need to pay fee for contract call, but if a contract method does lots of work, you need to add gas in contract call to prevent DoS attack like this: contract.method.call({gas: ...
5
votes
1answer
961 views

What's the difference in the ways of calling a contract function?

After I get an instance of a contract, there are 3 ways to call the contract function below: 1.testInstance.testfunc({from:eth.accounts[0]}) 2.testInstance.testfunc.sendTransaction({from:eth.accounts[...
4
votes
3answers
98 views

Can a “forward” smart contract forward the received ether to another “forward” smart contract which forwards it to an address?

I am pretty new to solidity. I am trying to create a smart contract which deploys another smart contract and transfers ether to the newly created contract when a payment greater than 0.01 ether is ...
4
votes
2answers
134 views

Call Smart Contract every 5 Second

Is it possible the call a method of a smart contract every 5 seconds? Lets say i want to call a webservice or an other smart contract in order to get the actual value? That is not possible or? In ...
4
votes
1answer
4k views

How to Set Gas Price in Private Blockchain?

I admit that I don't understand Gas at all. But I think it is basically the currency which dapps use to interact with each other and the blockchain. Yes? If you're creating a custom/private network,...
4
votes
1answer
2k views

Where exactly do DApps run? Who gets rewarded for running them? [duplicate]

So I am currently running a full node, as well as a GPU miner. I am curious first of all where do DApps get run? They wouldn't make sense to run on a GPU as they aren't very parallizable, so I am ...
3
votes
3answers
4k views

What is the point of variable transaction fees in Ethereum (and Bitcoin as well)?

After reading through the docs and through this post, I understand the concept and need for gas, but I do not understand why each transaction can have a variable fee associated with it. It seems to be ...
3
votes
1answer
621 views

what is difference between “gas” “gas price” and “fee”?

Can we say that gas is the unit of transaction fee ? And gas price is the same transaction fee ? If so, why we do not use ether and wei instead of gas ?
3
votes
1answer
1k views

When calling a smart contract function, who gets paid and how much does the caller pay?

This is an extended question to What is "gas" and transaction fee in Ethereum?. Who gets paid and how much does the caller pay? Let's make some assumptions: There is a function F which ...
2
votes
2answers
3k views

If the price of ether coin goes up, does it mean less likely people are going to build application on the ethereum network?

If I am not mistaking, application developers need to pay using ether coins to have their application hosted on the ethereum network. So if the price of ether keeps going up like it is now, doesn't it ...
2
votes
2answers
16k views

How much is 1 gas in ether? [duplicate]

On Etherscan the daily GasUsed chart shows current usage of 10-15 bill. How do I convert this correctly to ether (ETH)?.
2
votes
2answers
626 views

why are Transactions paid in Gas and not just Ether directly [duplicate]

All the explanations I heard for the Gas usage, could imho also be dealt with in Ether directly. What is it that Gas does that couldn't be done with Ether directly?
2
votes
1answer
30 views

Should I pre-buy gas to effect ethereum transaction?

I am new to ethereum. I have a few questions. Should I pre-buy gas to effect ethereum transactions? Or can I just set what is the gas price I am willing to pay so that at the time of transaction the ...
2
votes
1answer
402 views

EVM opcodes-prices

1) Why are opcodes in Ethereum priced the way they are priced and why is the EVM so expensive? 2) Right upfront, I do not say that it is too expensive to perform a tx on Ethereum, I just say that ...
2
votes
1answer
318 views

Digital asset management dapp using Ethereum

I am new to ethereum and also I have tried out some examples for building smart contract using truffle and ganache. But I want to make Digital asset management dapp using ethereum. Like, if have I ...
2
votes
2answers
504 views

ERC20 Transaction Fee - setFeeCurrency

Hi i now read everywhere that a transaction fee has to be paid in ETH. But I also found via the ethereum page the following page: https://github.com/ethereum/wiki/wiki/Standardized_Contract_APIs#...
2
votes
1answer
236 views

Solidity browser compiler crashes

It seems like every time I try to execute a contract function through the browser compiler that requires more than around 50k gas (give or take) to execute, the browser tab's memory gets to around 1GB ...
1
vote
3answers
66 views

Can blockchain technology can ever be useful if the currency conversion to fiat money is volatile? [closed]

From my limited understanding of blockchain technology in general and ethereum in particular, whatever the token, or ether that this technology uses, eventually it has to be related to fiat money. Eg: ...
1
vote
2answers
215 views

Why is my account balance after executing the contract so different?

I'm writing a test for a Lottery contract: var Lottery = artifacts.require("./Lottery.sol"); contract('Lottery', function (accounts) { var ACC_FABIAN = accounts[0]; var ACC_RENE = accounts[1]...
1
vote
1answer
99 views

What would be the cost of this transaction to end user?

A simple question on gas spent on a transaction here. I'm experimenting with testnet transaction on a simple contract that stores a value, trying to figure out how much a client would pay. What would ...
1
vote
1answer
85 views

How to do performance evaluation?

How to do the performance evaluation in terms of secs or minutes? what is the command to use in solidity?
1
vote
1answer
47 views

Transaction fees in ethereum [duplicate]

I have created an ERC20 token, but whenever I want to trnasfer it, transaction fees is deducted in ethers. But I donot want to but ethers. Cant the fee be deducted in terms of my custom token? Thanks
1
vote
0answers
40 views

What's the point in the 'gas' parameter passed to function 'signTransaction'? [duplicate]

I am using web3.js v1 in order to sign and send transactions: async function signAndSend(transaction) { let options = { to : transaction._parent._address, data: transaction....
1
vote
0answers
24 views

Does only one miner collect my transaction fee? [duplicate]

I just ran in to the concept of gas and found this community. This question and answer were particularly helpful, but they leave one thing unanswered for me: If I send out a transaction with a given ...

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