Trending questions in Blockchain

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truffle migrate Error

testrpc Check your truffle.js config port and ip ...READ MORE

Oct 8, 2018 in Blockchain by Omkar
 • 69,220 points • 1,313 views
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1 answer

Bitcoin: parsing Blockchain API using JSON

Because you only add one address to ...READ MORE

Aug 22, 2018 in Blockchain by digger
 • 26,740 points • 3,340 views
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1 answer

How can I deploy a hyperledger business network using docker-compose?

If you want to use Composer, be ...READ MORE

Oct 4, 2018 in Blockchain by Perry
 • 17,100 points • 1,480 views
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1 answer

Are there null like thing in solidity

You could create none variable to use it as ...READ MORE

Sep 21, 2018 in Blockchain by digger
 • 26,740 points • 2,040 views
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1 answer

Why do the resultant hash after mining has a leading no. of zeroes in Blockchain verification?

This is chosen by the DIFFICULTY EQUATION. In ...READ MORE

Aug 10, 2018 in Blockchain by Christine
 • 15,790 points • 3,811 views
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1 answer

pubToAddress method from ethereumjs-util throws AssertionError: false == true

This code works fine: var keythereum = require('keythereum'); var ...READ MORE

Oct 8, 2018 in Blockchain by Omkar
 • 69,220 points • 1,269 views
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1 answer

Test ethereum Event Logs with truffle

You are passing tx hash into done() ...READ MORE

Sep 21, 2018 in Blockchain by slayer
 • 29,370 points • 1,977 views
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1 answer

How to define the path to hyperledger-fabric chaincode?

You can find that in docker-compose files ...READ MORE

Oct 4, 2018 in Blockchain by Perry
 • 17,100 points • 1,413 views
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1 answer

Hyperledger Composer Incompatible versions error

The versions are same. Maybe its a ...READ MORE

Oct 24, 2018 in Blockchain by Omkar
 • 69,220 points • 528 views
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1 answer

Is it possible to send eth to a contract through its constructor from another contract?

I found the solution for this: pragma solidity ...READ MORE

Sep 26, 2018 in Blockchain by slayer
 • 29,370 points • 1,738 views
0 votes
1 answer

What is the difference between creating a new solidity contract with and without the `new` keyword?

You cannot omit new keyword for creating ...READ MORE

Oct 8, 2018 in Blockchain by Omkar
 • 69,220 points • 1,198 views
0 votes
1 answer

TypeError: XMLHttpRequest is not a function when using web3 on meteor server side

I had the same problem. Instead ethereum:web3 Meteor package ...READ MORE

Oct 10, 2018 in Blockchain by Omkar
 • 69,220 points • 1,101 views
0 votes
2 answers

How to check if bitcoin address is valid?

For Java, have a look at the ...READ MORE

Aug 20, 2018 in Blockchain by Omkar
 • 69,220 points • 3,259 views
0 votes
3 answers

UnhandledPromiseRejectionWarning: Error: The contract code couldn't be stored, please check your gas limit

I believe bytecode is being treated as ...READ MORE

Sep 24, 2018 in Blockchain by Teja
 • 1,688 views
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1 answer

How to fix browser/IERC20.sol:4:53: Warning: This declaration shadows an existing declaration

I believe the issue is the reuse ...READ MORE

Oct 1, 2018 in Blockchain by slayer
 • 29,370 points • 1,460 views
0 votes
1 answer

Historical ethereum prices - Coinbase API

def get_spot_price(self, **params): """https://developers.coinbase.com/api/v2#get-spot-price""" ...READ MORE

Sep 21, 2018 in Blockchain by digger
 • 26,740 points • 1,877 views
0 votes
1 answer

How to efficiently hash (SHA 256) in golang data where only the last few bytes changes

You can try the following examples on ...READ MORE

Jun 27, 2018 in Blockchain by aryya
 • 7,460 points • 5,580 views
0 votes
1 answer

Ethereum serpent version conflict error.

Upgrade to the lastest version of ethereum-serpent ...READ MORE

Oct 24, 2018 in Blockchain by Omkar
 • 69,220 points • 447 views
0 votes
1 answer

How do I send ether from an EOA to a smart contract?

You include ether to send in the ...READ MORE

Sep 27, 2018 in Blockchain by digger
 • 26,740 points • 1,604 views
+1 vote
1 answer

Solidity: Sending ERC20 Tokens

You can try this code transferTokensTo: function(contract, address_from, ...READ MORE

Sep 26, 2018 in Blockchain by slayer
 • 29,370 points • 1,573 views
0 votes
1 answer

Go build fail, fatal error: rocksdb/c.h

I followed here and it is done. https://github.com/openblockchain/obc-peer/issues/885 Configure ...READ MORE

Sep 17, 2018 in Blockchain by slayer
 • 29,370 points • 1,996 views
+1 vote
3 answers

Pass all .dat files in folder to function

os.listdir(path) return names, not fullpaths change parseBlockFile(file) to fullpath = os.path.join(path,file) if os.path.isfile(fullpath) ...READ MORE

Sep 5, 2018 in Blockchain by Saygum
 • 2,396 views
0 votes
1 answer

How do Ethereum node compete for blocks?

Yes, all the nodes do compete for ...READ MORE

Oct 12, 2018 in Blockchain by Perry
 • 17,100 points • 876 views
0 votes
1 answer

Not able send ether to my smart contract's address

It turns out that you need to create ...READ MORE

Sep 25, 2018 in Blockchain by slayer
 • 29,370 points • 1,608 views
0 votes
1 answer

Python Script to pull data from Blockchain JSON

Try this: print r.json()['address'],' has ', r.json()['n_tx'], 'tr ...READ MORE

Sep 14, 2018 in Blockchain by digger
 • 26,740 points • 2,079 views
0 votes
1 answer

Ethereum generating genesis Python Syntax

print in python3 is a method not a ...READ MORE

Oct 10, 2018 in Blockchain by Omkar
 • 69,220 points • 946 views
0 votes
1 answer

sellprice and buyprice fixing in smart contract.

It is due to the fact you ...READ MORE

Oct 17, 2018 in Blockchain by Christine
 • 15,790 points • 617 views
0 votes
1 answer

How can I inject and use this javascript library (web3) with JavascriptCore

The web3.js library has dependencies on bignumber.js and crypto-js.js (See dependencies here). You will ...READ MORE

Oct 8, 2018 in Blockchain by Omkar
 • 69,220 points • 968 views
0 votes
1 answer

Where is the geth.exe in the Ethereum mist?

In Windows, you will find geth.exe in ...READ MORE

Oct 10, 2018 in Blockchain by Omkar
 • 69,220 points • 871 views
0 votes
1 answer

Poloniex C# API - get trades

Outputting the Trade will just show you ...READ MORE

Sep 25, 2018 in Blockchain by digger
 • 26,740 points • 1,511 views
0 votes
1 answer

403 forbidden error coinbase api

I had a similiar issue connecting this API, ...READ MORE

Aug 28, 2018 in Blockchain by digger
 • 26,740 points • 2,672 views
0 votes
1 answer

Solidity different token price

Yes you can do this by modifying ...READ MORE

Oct 8, 2018 in Blockchain by Omkar
 • 69,220 points • 899 views
0 votes
1 answer

Nethereum C# Unit Test GetTransactionCount

You have already made the test async ...READ MORE

Sep 26, 2018 in Blockchain by slayer
 • 29,370 points • 1,404 views
0 votes
1 answer

Why estimateGas always returns null or zero?

The Web3 API uses error first style callbacks. Your ...READ MORE

Sep 28, 2018 in Blockchain by digger
 • 26,740 points • 1,308 views
0 votes
1 answer

How can I create an online wallet without any 3rd party API on my PHP server?

With any approach, you need a bitcoin ...READ MORE

Aug 30, 2018 in Blockchain by Perry
 • 17,100 points • 2,579 views
0 votes
1 answer

Solidity: How can I return a list of user-defined function?

You can do it with something like ...READ MORE

Sep 26, 2018 in Blockchain by digger
 • 26,740 points • 1,384 views
0 votes
2 answers

Warning: Using contract member “balance” inherited from the address type is deprecated. Solidity

Alternatively you could assign this to a local variable ...READ MORE

Oct 3, 2018 in Blockchain by Rustom
 • 1,202 views
0 votes
1 answer

What happens to Ether in a smart contract after selfdestruct?

selfdestruct takes one argument an address and then sends all ...READ MORE

Oct 3, 2018 in Blockchain by digger
 • 26,740 points • 1,069 views
0 votes
1 answer

Getting the length of public array variable (getter)

The calling contract will need the ABI ...READ MORE

Sep 24, 2018 in Blockchain by digger
 • 26,740 points • 1,448 views
0 votes
1 answer

BitcoinJ generate address from private key

Convert string private key into bytes[]: ECKey key = ...READ MORE

Sep 4, 2018 in Blockchain by slayer
 • 29,370 points • 2,299 views
0 votes
1 answer

Sending hash in function parameter

I am developing a smart contract using ...READ MORE

Oct 8, 2018 in Blockchain by Omkar
 • 69,220 points • 814 views
0 votes
1 answer

Solidity mocha : address is not a contract error

Try the following: // Initialize contract variable with ...READ MORE

Oct 1, 2018 in Blockchain by digger
 • 26,740 points • 1,112 views
0 votes
1 answer

Solidity how to solve “Error Encoding arguments ” error while using create button?

When you pass multiple arguments, you need ...READ MORE

Jul 30, 2018 in Blockchain by slayer
 • 29,370 points • 3,847 views
0 votes
1 answer

Solidity invalid opcode error

In the for loop, your indexing going ...READ MORE

Aug 16, 2018 in Blockchain by slayer
 • 29,370 points • 3,088 views
0 votes
1 answer

Go- Chaincode function to display struct values

Try this func (t *SimpleChaincode) setDetails(stub shim.ChaincodeStubInterface, args ...READ MORE

Sep 19, 2018 in Blockchain by digger
 • 26,740 points • 1,616 views
0 votes
1 answer

How to allow request from host machine and deny from other machine, using ethereum in docker?

You can restrict access to the port ...READ MORE

Oct 9, 2018 in Blockchain by Omkar
 • 69,220 points • 751 views
0 votes
1 answer

How to convert byte array to hex string?

You are missing the padding in the ...READ MORE

Aug 17, 2018 in Blockchain by slayer
 • 29,370 points • 3,036 views
0 votes
1 answer

Truffle tests not running after truffle init

This was a bug. They've fixed it. ...READ MORE

Sep 11, 2018 in Blockchain by Christine
 • 15,790 points • 1,954 views
0 votes
1 answer

Cant decode hex sting into decimal. Getting TypeError.

On the line where it shows error, ...READ MORE

Jul 6, 2018 in Blockchain by slayer
 • 29,370 points • 4,844 views
0 votes
1 answer

I am not able to change array elements globally

Remove the constant modifier from getArray(). constant functions do not write state ...READ MORE

Oct 9, 2018 in Blockchain by Omkar
 • 69,220 points • 724 views
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