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13 answers

TX doesn't have the correct nonce - Metamask

I'm trying to call the leafPicked() function in my contract from web3 which launches Metamask as intended. After pressing accept the transaction shows as failed along with the error message pictured below. What am I doing wrong? Contract…
Charles
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1 answer

What is the exact meaning of a transaction's new receipt 'status' field?

In this answer (https://ethereum.stackexchange.com/a/6010/1529) it seems to say that the status field will always be '1' unless the transaction failed, in which case it will be '0'. In the summary section of this answer…
Thomas Jay Rush
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24
votes
2 answers

What's the best hardware for Mining Ether?

As my title says, I am a complete newbie to the Ethereum Project, but not to the cryptography in general. Although this will be the first time I will consider investing in the mining process. And I just would like to know, what is the best current…
Lewis
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24
votes
2 answers

Why are local variables allocated to storage instead of memory?

Local variables (i.e. variables declared inside functions) are held in persistent storage by default instead of non-persistent memory (source). The value of a local variable can not persist in between function invocations, so in my mind it makes…
Harry Wright
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24
votes
3 answers

What does the Web3 "BigNumber not a base 16 number Error" mean

Is there a known problem with parsing events containing strings in Truffle/Web3? I'm using truffle with the following simple contract contract Board { string foo; event Shout(); event TextEvent( string indexed text, …
JackWinters
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24
votes
6 answers

Is there a GPU-hashrate database?

Is there a database that lists GPU models and their approximate mining hashrates?
jeff
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24
votes
3 answers

How can i tell if geth is done running?

Well i am new trying to mine and i did the "C:>geth --rpc" and its still going how will i know when its done? i did all the steps leading to this but my pc just keeps running the INFO [05-18|23:32:54] Imported new block receipts …
Gilbert
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24
votes
1 answer

Mapping with array as Key Or Value data type

Is it possible to do a mapping with an Array as key/value ? Where an array would exist for each value ? I'm actually looking to store structs in a mapping but can't seem to have it work. Struct Foo{ uint x } mapping(uint => Foo[])foo; and even…
jayD
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24
votes
2 answers

How does Ethereum deal with blockchain scalability?

The Bitcoin community are currently trying to solve the problems of blockchain scalability. Some are advocating an increase in block size, others are talking about things like Segregated Witness. Lots of arguments have ensued. Firstly, what is the…
Richard Horrocks
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24
votes
2 answers

What is an Enode ID in Ethereum?

What is the definition of an Enode ID or Enode URI? What is it used for and how is it made?
Hudson Jameson
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24
votes
3 answers

Power operations in solidity

Does solidity supports power operations like 2^3 = 8 or should I perform multiple multiplications? Should i include a math library? I don't find anything in the official doc. Thanks
Arslan Smal
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24
votes
2 answers

Throw vs. Return

We're trying to figure out whether to use return or throw in Solidity when a condition fails and we don't assume user maliciousness. Here's the pros and cons we've figured so far: Why use throw Any side effects of the code are reverted Some wallets…
ronme
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24
votes
4 answers

Estimate gas price with ethers.js

I'm looking to estimate transaction fees in an application. In order to do so I need to estimate the current gas price before I execute the transaction. I see web3.js has a getGasPrice…
Sam Richards
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23
votes
3 answers

How to generate a unique identifier in Solidity?

I am making a student registration form and need a unique identifier for them. Are there any methods in Solidity that will give a unique number for every student that registers?
Rahul Sharma
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23
votes
1 answer

What is the difference between a pending transaction and a queued transaction in the geth mempool?

I see the following on the wiki but I dont understand the difference pending: all processable transactions queued: all non-processable transactions
bamos
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