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1500 questions
21
votes
2 answers
get array.length without a getter from other contract?
Is there a way to get length of an array in an other contract without a getter?
pragma solidity ^0.4.11;
contract MyContractA {
uint[] public myArray;
function MyContractA() {
myArray.length = 1;
}
}
contract MyContractB {
…
szerte
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21
votes
6 answers
How to find contract's address?
I successfully setup a private blockchain and created the "hello world" contract according to tutorial from etherium web site. One thing that I can't figure out is how to find the contract later. I thought once the contract is mined, it becomes…
user3280964
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21
votes
6 answers
Is there any hardware wallet available for Ethereum?
What are the various available hardware wallets for Ethereum?
rethsid
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21
votes
1 answer
Is Ethereum ASIC resistant?
I've heard that Ethereum mining is ASIC resistant since it requires memory-hard hashing algorithms. However, why can't miners buy large DRAM and devote the memory to ASIC mining? What prevents miners from making an ASIC paired with large…
Hwang
- 343
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21
votes
1 answer
Out of Gas invoking precompiled contracts on private blockchains
Why do precompiled contracts lead to Out of Gas on private blockchains?
Some tidbits are provided in the Solidity docs but can it be explained more?
It might be that you run into Out-of-Gas for sha256, ripemd160 or
ecrecover on a private…
eth
- 85,679
- 53
- 285
- 406
21
votes
1 answer
The meaning/specification of "config" in genesis.json
As I tried to search from Google, there are some genesis.json example files to customize the parameter of genesis block in Ethereum private blockchain.
In the file, there is a part called "config"
"config": {
"chainId": 1,
"homesteadBlock":…
Thomas Lau
- 385
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21
votes
7 answers
geth import vs copying chaindata
I'm trying to sync my RPi 2 with the blockchain.
geth import runs quite slowly, as well as syncing from scratch.
What would be the problem in just copying the .ethereum/chaindata folder from another fully synced ethereum node?
Thibaut Schaeffer
- 351
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21
votes
1 answer
What is the order and concurrency behavior of multiple calls to a contract in a single transaction?
Suppose a contract has three call APIs that have side effects.
What's the behavior if I try to:
Call all three APIs from one address (i.e. issue three transactions if from nodejs). Are all three mined simultaneously? In what order?
Same question,…
Paul S
- 4,271
- 1
- 22
- 48
21
votes
2 answers
How to read a private variable from a contract?
Given a contract, how can I find out the current value of one of its variables (as a dev, not from the context of another contract), if it's not public?
ronme
- 1,035
- 1
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21
votes
7 answers
What are Storj and Sia and how different are they from Swarm and IPFS
I have recently discovered some blockchain based storage technologies like Storj and Sia.
I have vaguely understood that they rely on their own blockchain with their own cryptocurrency.
But why are they not relying on preexisting blockchains like…
mhham
- 373
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21
votes
2 answers
How do I remove accounts using the Geth console?
I have several accounts I've created in the Geth console using:
personal.newAccount()
I no longer use (nor have any intention of using) the first couple of accounts I created, meaning whenever I reference an active account I have to set the account…
Richard Horrocks
- 37,835
- 13
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21
votes
3 answers
Fundamental limitations between Solidity and Serpent
Solidity can be considered a "higher level" language than Serpent.
Are there any "low level" features in Serpent or that could be implemented in Serpent, that are either impossible or infeasible to do with Solidity?
If there are, an order from…
eth
- 85,679
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- 285
- 406
21
votes
5 answers
How to know if a transaction went through or not? (out of gas)
Apparently when sending transactions from an Account instead of a Wallet, the gas spent is small (21K), and not enough to send ether to a Contract Wallet (out of gas, so to speak).
When this happens, the transaction shouldn't go through (or be…
knocte
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21
votes
2 answers
Oracle (oraclize.it) with Truffle and Testrpc
As I understood in the blockchain, it is "not" possible to interact with webservices outside the blockchain. This must be done over oracles in order to verfiy that the request is secure, and the state change can be done in the blockchain. Please…
Wi1616
- 521
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- 8
21
votes
2 answers
Is it safe to reuse Ether addresses?
I believe it's viewed as unsafe in Bitcoin because of the way transactions are signed. Is this also true for Ether addresses?
clewisjr1
- 261
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