Latest questions in Blockchain

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
• 29,350 points
1,346 views
0 votes
1 answer

Why Gas Used By Txn is different when invoking the same function in the same smart contract?

The input data might be different, but ...READ MORE

Sep 25, 2018 in Blockchain by Christine
• 15,790 points
744 views
0 votes
1 answer

How to detect if an ethereum address is an ERC20 token contract?

There are many possible ways to achieve ...READ MORE

Sep 25, 2018 in Blockchain by Christine
• 15,790 points
7,126 views
+2 votes
1 answer

Composer playground - issue on RHEL

Hey, Renu353. There could be more than ...READ MORE

Sep 24, 2018 in Blockchain by Omkar
• 69,230 points
899 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
1,206 views
0 votes
4 answers

Unable to run truffle@2.1.2 migrate --network live. “Exceeds block gas limit”

A simple solution to avoid this is: module.exports ...READ MORE

Sep 28, 2018 in Blockchain by Ludo
1,382 views
0 votes
1 answer

ethminer failed to submit hashrate

The pool you are linking with the -F flag ...READ MORE

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

How to manually create the instance of the contract in truffle?

You can try to do it like ...READ MORE

Sep 24, 2018 in Blockchain by slayer
• 29,350 points
2,472 views
0 votes
1 answer

Repeating transactions hangs - web3js, local geth

If you are sending transactions back-to-back from ...READ MORE

Sep 24, 2018 in Blockchain by digger
• 26,740 points
875 views
0 votes
2 answers

Is it possible to modify a variable value from another contract?

No, you can't directly edit a variable ...READ MORE

Sep 24, 2018 in Blockchain by Sai
4,005 views
+1 vote
3 answers

What is the pattern for handling throw on a Solidity contract in tests

In my opinion the cleanest way is: it("should ...READ MORE

Sep 25, 2018 in Blockchain by Lupin
1,566 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
1,389 views
0 votes
2 answers

Truffle migrate Error after run testrpc

Simple Solution: // module.exports = { // ...READ MORE

Sep 24, 2018 in Blockchain by Wasim
617 views
0 votes
1 answer

Not able to send Ethereum transaction

Hey, Change this line: await crowdsale.sendTransaction({value, from: buyer, gas: ...READ MORE

Sep 24, 2018 in Blockchain by slayer
• 29,350 points
502 views
+3 votes
1 answer

What is the difference between online and offline hyperledger composer?

Hey @Renu353! Well, it's good that you ...READ MORE

Sep 21, 2018 in Blockchain by Omkar
• 69,230 points
686 views
0 votes
1 answer

Can't send transaction even if I use an example from official Ethereum webpage

As I understand your question you are ...READ MORE

Sep 21, 2018 in Blockchain by slayer
• 29,350 points
973 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
1,673 views
0 votes
1 answer

Test ethereum Event Logs with truffle

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

Sep 21, 2018 in Blockchain by slayer
• 29,350 points
1,836 views
0 votes
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
1,691 views
0 votes
1 answer

String concatenation in solidity?

A library can be used, for example: import "github.com/Arachnid/solidity-stringutils/strings.sol"; contract C ...READ MORE

Sep 21, 2018 in Blockchain by slayer
• 29,350 points
3,164 views
0 votes
1 answer

What do I import for SHA encryption in Node.js?

var sha = require('sha.js'); //... getHash() { ...READ MORE

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

how loop through a JSON Array of bitcoin transaction data

for($i=0; $i<count($result['out']); $i++) { echo ...READ MORE

Sep 21, 2018 in Blockchain by slayer
• 29,350 points
546 views
0 votes
1 answer

Syntax Error running on Python

You are missing the closing parenthesis: hashlib.sha256(self.index + ...READ MORE

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

Why do people prefer mining Litecoin over Bitcoin?

The main reason people prefer mining Litecoin ...READ MORE

Sep 21, 2018 in Blockchain by slayer
• 29,350 points
513 views
0 votes
1 answer

How to Query hdfs with Spark Sql

Yyou can achieve this by creating Dataframe. val ...READ MORE

Sep 20, 2018 in Blockchain by slayer
• 29,350 points
1,885 views
0 votes
1 answer

How to send JSON object from npm module to browser

A simple solution for this would be ...READ MORE

Sep 20, 2018 in Blockchain by digger
• 26,740 points
528 views
0 votes
1 answer

Blockchain ToBTC API not returning Php variable

Seems like you have a syntax error ...READ MORE

Sep 20, 2018 in Blockchain by digger
• 26,740 points
440 views
0 votes
1 answer

XMLHttpRequest is not defined while sending request to blockchain service via C#

use post data in url link and ...READ MORE

Sep 20, 2018 in Blockchain by slayer
• 29,350 points
1,032 views
+2 votes
1 answer

Has Blockchain made illegal activities easier?

Not really.. The transparency of Blockchain makes ...READ MORE

Sep 20, 2018 in Blockchain by Sumit
318 views
+2 votes
1 answer

What is Bitcoin Powered Electrical Outlet?

Bitcoin powered electrical outlet is nothing but ...READ MORE

Sep 20, 2018 in Blockchain by Bhaskar
533 views
+1 vote
1 answer

Ethereum vs Hyperledger: Which is better for business networks?

Hyperledger is preferred for B2B business and ...READ MORE

Sep 20, 2018 in Blockchain by digger
• 26,740 points
525 views
+1 vote
1 answer

Can't instantiate any chaincodes on peers of newly Added org

Seems like chaincode install may have been unsuccessful. Before ...READ MORE

Sep 20, 2018 in Blockchain by Perry
• 17,100 points
1,881 views
0 votes
1 answer

How to extend Composer rest Server ?

 It looks like you want to query ...READ MORE

Sep 20, 2018 in Blockchain by Perry
• 17,100 points
658 views
0 votes
1 answer

How to create an asset on Bigchaindb server using http call

You could start like this: method = POST URL ...READ MORE

Sep 19, 2018 in Blockchain by Christine
• 15,790 points
1,152 views
0 votes
1 answer

Public key encoding changes

You are printing the memory address of ...READ MORE

Sep 19, 2018 in Blockchain by Christine
• 15,790 points
416 views
0 votes
1 answer

Docker on mac error message can't connect to Docker endpoint

While CORE_VM_ENDPOINT set to unix:///var/run/docker.sock, please make sure that var/run/docker.sock exists in ...READ MORE

Sep 19, 2018 in Blockchain by slayer
• 29,350 points
1,943 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
1,411 views
0 votes
1 answer

How to Read multiple value from as JSON format from a external service and store in composer registry

Hey buddy,  this works: /** * Track temperatures ...READ MORE

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

Nodejs: How to pass user form data into defined class

This should do your work: // select the ...READ MORE

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

JavaFX Location is not set error message

I had this problem and found this ...READ MORE

Sep 19, 2018 in Blockchain by slayer
• 29,350 points
9,115 views
+1 vote
2 answers

Peer chaincode instantiation timeout expired

Hey, i think you made a slight ...READ MORE

Sep 19, 2018 in Blockchain by digger
• 26,740 points
3,117 views
0 votes
1 answer

Decorators in Hyperledger Composer Modeling Language

Define you CustomAsset like mentioned below and ...READ MORE

Sep 19, 2018 in Blockchain by slayer
• 29,350 points
563 views
0 votes
1 answer

Sawtooth Javascript SDK "Batchlist rejected" error

What you can do is use intkey-client to the ...READ MORE

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

How to Check if string is in list in javascript?

At first, make sure that the string ...READ MORE

Sep 19, 2018 in Blockchain by slayer
• 29,350 points
2,629 views
0 votes
1 answer

When trying to Start the membersrvc, its not responding!

You should start membersrvc at first in ...READ MORE

Sep 19, 2018 in Blockchain by Christine
• 15,790 points
459 views
0 votes
1 answer

Corda: uploading a file, attach and download

Hey, i found an example that i ...READ MORE

Sep 19, 2018 in Blockchain by digger
• 26,740 points
1,210 views
0 votes
1 answer

Can we set a list of discovery nodes in Hyperledger fabric?

New nodes doesn't depend on a single ...READ MORE

Sep 19, 2018 in Blockchain by Christine
• 15,790 points
768 views
0 votes
1 answer

How to handle Overlapping of array objects in node js

Try this code, may be it works for ...READ MORE

Sep 18, 2018 in Blockchain by digger
• 26,740 points
629 views
0 votes
1 answer

How to decrypt result of query when using the Hyperledger Client SDK for Node.js

In this case, it is just a ...READ MORE

Sep 18, 2018 in Blockchain by slayer
• 29,350 points
452 views
0 votes
1 answer

How to connect to already running go ethereum client using mist Ubuntu

Hey, you can solve the issue by using sudo ...READ MORE

Sep 18, 2018 in Blockchain by digger
• 26,740 points
556 views