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1500 questions
14
votes
1 answer
Issue with "Generating Transaction" with MEW offline
I would like to try to send offline with MEW.
I'm using a pc with Window 7, no sp1, never been connected.
I have tried with Firefox and Chrome.
Been cleaning cache, rebooting.
Nothing happens when I click on "Generate Transaction".
Gaab
- 381
- 2
- 6
14
votes
2 answers
How do Enums work?
I am just starting out with Solidity and JavaScript and am trying to understand Enums. I have a simple contract
pragma solidity ^0.4.4;
contract SimpleEnum {
enum SomeData {Channel}
SomeData sd;
function set_values(uint a) {
sd.Channel…
Wapiti
- 419
- 1
- 4
- 9
14
votes
3 answers
Can Mist be attached to a Geth node on a different computer over HTTP RPC?
I gather that Mist will automatically look for Geth on a local machine via IPC to save it maintaining its own blockchain. Is it possible to tell it to look for an instance of Geth on another machine via HTTP RPC?
tallguin
- 143
- 1
- 5
14
votes
2 answers
What is the Long-Range-Attack in Proof-of-Stake?
What is the Long-Range-Attack in Proof-of-Stake? And how will this vector be mitigated with the Casper Proof-of-Stake implementation?
q9f
- 32,913
- 47
- 156
- 395
14
votes
3 answers
How to whitelist up to 50k addresses in a single contract?
What is the best practice in whitelisting a large amount of addresses in a contract. For example, if I wanted to include 50k addresses into a mapping that will reflect true for only the 50k addresses, would this be the optimal way? How much would…
blockchaindotsol
- 327
- 1
- 3
- 12
14
votes
2 answers
What is the latest secure and compatible token standard?
Most tokens are ERC20 tokens with varying implementations, and varying protections against bugs. However, there is the ERC223 token standard, which is an attempt to fix some of the problems in ERC20. It seems to be at least somewhat backward…
Nakedible
- 191
- 5
14
votes
3 answers
How can I instantiate an array of addresses?
I simply want to create an array with stuff in it. Everything I try is an error message in mist. Even this code snippet I got straight from the docs wont compile:
contract C {
uint someVariable;
uint[] data;
function f() {
uint[]…
ZMitton
- 2,750
- 4
- 19
- 34
14
votes
3 answers
Do users of ERC20 coins need to hold Ether?
Suppose there exists Fancycoin, an ERC20 altcoin which has some functionality implemented by the EVM. It does some nontrivial things that take up gas.
According to my understanding, I can receive Fancycoin in my wallet if somebody sends it to me,…
Wapiti
- 419
- 1
- 4
- 9
14
votes
1 answer
Error calling a function from another contract: Member "*" not found or not visible after argument-dependent lookup in type
I'm having trouble compiling a contract that calls a function of an imported contract.
SilverCoin.sol:
pragma solidity ^0.4.11;
contract SilverCoin {
function abc() constant returns (uint) {
return 0;
}
}
Banker.sol:
pragma…
rohithpr
- 418
- 2
- 4
- 16
14
votes
3 answers
What is the Private Key?
I am trying to understand what is the private key in Ethereum. Help please.
Private key = the address?
Private key = the password/passphrase?
Private key = the text seen when we open the file in the keystore folder?
Private key = something other…
Ashish Sinha
- 901
- 3
- 10
- 18
14
votes
0 answers
How can I update contracts after they are created?
Once I create a smart contract and submit it to the blockchain, how can I go about updating it? I might want to do this because I have found a bug in the current version, I want to change some of the settings or simply release a new and improved…
J-B
- 8,941
- 16
- 46
- 77
14
votes
1 answer
Why isn't fast sync the default?
As I understand, fast sync has all the security guarantees of a full sync, but is faster. Is that correct? If so, why isn't fast sync the default?
Randomblue
- 2,610
- 2
- 17
- 38
14
votes
3 answers
Is there a functional equivalent to Factom in Ethereum?
Factom is a distributed data and records management and audit system. How easily can what Factom does be done in Ethereum? Are there any working DAPPS doing this? Could a simple smart contract take care of such a function?
Joël
- 1,720
- 2
- 17
- 35
14
votes
4 answers
Error encountered during contract execution [Bad instruction]
I don't understand why if i execute my function with web3.js i obtain this error in the transaction:
Warning! Error encountered during contract execution [Bad instruction]
I read this other question about the same error. I don't understand why with…
Gawey
- 814
- 2
- 8
- 23
14
votes
4 answers
Solidity: accessing a library constant in a contract that imports the library
Is it possible to access a library constant in a contract that imports the library?
I am using solidity 0.4.11
For instance:
library Lib {
bytes1 constant flag = 0x01
...
}
separate file
import Lib
contract A {
bytes1 x = (I have…
Jake Gillberg
- 141
- 1
- 5