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1500 questions
10
votes
2 answers
How to create private network with preallocated amount of ETH?
I am trying to create a private network for testing purposes. What I need is:
Fast generating of DAG file.
Fast mining of the first block.
Address with some preallocated amount of Eth.
I found that this could be done by two ways, the first one…
Andrey Samokhvalov
- 364
- 3
- 10
10
votes
2 answers
How to create Sidechain?
I have two questions regarding sidechain.
Q1. Do we need specific technology stack to create sidechain ?
Q2. Can any public blokchain can be use for sidechain ? also how can i use sidechain with Ethereum.
looking forward
Thanks!
Waris Ahmed khan
- 143
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- 6
10
votes
0 answers
geth vs parity - quantitative comparison
How do geth and parity Ethereum nodes compare in terms of:
Speed
How long does it take to sync with the main net, in both fast and full modes (if possible)
Disk space needs
What is the size of the chain data in fast and full modes
Robustness…
medvedev1088
- 10,996
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- 35
- 63
10
votes
2 answers
Why most ERC-20 Tokens Have 18 Decimals?
I don't really understand the fundamental rationale for this. I'd think 0 decimal is much simpler to understand for most people?
0xgoku
- 471
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- 16
10
votes
1 answer
Access to public variable from other contract
Unable to access to public variable in Test.sol contract from other contract. How to do it?
Test.sol contract
pragma solidity ^0.4.18;
contract Test {
uint256 public val = 256;
}
My attemps to access variable:
pragma solidity ^0.4.18;
import…
Mikky Snowman
- 195
- 2
- 2
- 10
10
votes
4 answers
What are the popular API to get current exchange rates for Ethereum to USD
Can you please list all the API providers for cryptocurrency to USD
Thanks in advance.
Muddassar Shaikh
- 145
- 1
- 3
- 13
10
votes
1 answer
What is the name of pool which keeps transactions in memory such as Bitcoin's mempool?
Do Ethereum clients have a memory pool which keeps transactions like Bitcoin's mempool?
If so, what is the name for it in Ethereum?
Satoshi Nakanishi
- 5,749
- 7
- 38
- 57
10
votes
1 answer
Iterating over all public values of a mapping in web3
Let's assume we have the standard token contract with balances:
mapping (address => uint256) public balanceOf;
If I want to know balances of all addresses (who have ever transacted with the contract) in web3, can I somehow construct this state?…
Mikko Ohtamaa
- 22,269
- 6
- 62
- 127
10
votes
2 answers
Invalid Solidity Type Tuple[]
I have a contract on the Ropsten test network and I am trying to return an array of structs but I am receiving the following error in my JS console.
I am including the following at the top of my contract
pragma solidity ^0.4.18;
pragma experimental…
ORStudios
- 443
- 5
- 13
10
votes
4 answers
How to watch log for all instances of a specific type of contract?
Attaching a watcher for every instance of a contract is not a good idea in terms of memory and CPU. So is there a way to watch for events from all instances of a contract i.e., by registering a single watcher for all instances of the contract.
Note…
Narayan Prusty
- 1,229
- 1
- 11
- 22
10
votes
2 answers
Using Ethereum for data encryption
I'm trying to find a way to use an ethereum address/solidity/web3 for text encryption , but i'm not even sure it's possible to get the public key from the address(hash of the pubkey) using secp256k1 to get the publickey ? or if there is any other…
user697
- 2,176
- 3
- 15
- 19
10
votes
1 answer
Data sharing on the private blockchain
Assuming that there are multiple parties on the private blockchain, few general questions on the private blockchain usage:
Can Personally identifiable information (PII) data be stored on blockchain? does it fall under good architecture?
Lets say…
Mac
- 103
- 5
10
votes
2 answers
Negative number passed to function with uint parameter
Consider the following simple contract:
pragma solidity ^0.4.16;
contract TestContract {
function add(uint256 amount) returns (uint256) {
require(amount > 0);
return 100 + amount;
}
}
I would expect that the result of this…
Oliver Schwab
- 103
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- 4
10
votes
1 answer
How do I compare the "scalability" capabilities between ethereum and bitcoin?
I'm trying to assess how they can be compared. Bitcoin can process 7 trans/sec, is there some equivalent on the Ethereum side? How should I think about this and what quantitative info should I use?
Mark J.
- 361
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- 6
10
votes
4 answers
Does parity include a console?
I can run geth console to get a command line interface spawned after launching geth. Similar also works for eth.
I tried parity console but that didn't work out.
~ $ parity console
Invalid arguments.
Usage:
parity daemon [options]
…
q9f
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