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Does truffle test mimic the exact network state of an actual migration?

I've defined a truffle migration step as follows: Deploy my 'main' smart contract, nothing out of the ordinary: var UniversityVoting = artifacts.require('./UniversityVoting.sol'); module....
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0answers
4 views

Update on the projected coin inflation for ethereum?

I've seen this question: What is Ethereum's inflation rate? (how quickly will new ether be created) but the answers are vague and out-of date I know that Bitcoin is halving and all coins will be ...
0
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1answer
8 views

The constructor should be payable if you send value. The transaction has been reverted to the initial state

I'm following a LinkedIn course on Solidity and creating a simple contract. Code below: I'm new to solidity so I'm not sure exactly where I'm going wrong but I get the following error: Transact to ...
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0answers
4 views

LocalEthereum Won't Let Me Create or Log In With Ledger

I have a Ledger Nano S and created a LocalEthereum account awhile ago by connecting my ledger to the account. It worked fine and I purchased some Ethereum. A few weeks later, I attempted to sign back ...
1
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0answers
9 views

Ethereum pruning: What if no archival node existed?

I was reading about pruning in Ethereum which is basically a way to run a full node without needing to keep over 1TB of blockchain data. To my understanding, the whole blockchain exists but only keeps ...
0
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1answer
11 views

How to modify the algorithm of transaction selection in Ethereum private net?

By default, miners select transactions with high fees from the mempool. So, transactions which are dependent and have a specific order can be selected randomly without respecting this order. Will I be ...
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2answers
15 views

Why are contacts from Remix editor and explorer different after deploying?

I try to deploy my ERC20 token. My steps are: 1) I created a contact with Remix (by some manual) https://gist.github.com/pistol88/a934da7fcaa93a92f4c4de60df56a0cf contract TestToken is ERC20Standard ...
0
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1answer
13 views

ecrecover() always returns 0x0000000000000000000000000000000000000000

I'm aware of these posts How do you sign an verify a message in javascript proving you own an Ethereum address? How does one properly use ecrecover to verify Ethereum signatures? I'd like to sign a ...
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1answer
27 views

Solidity - How do I generate a random address

I would like to generate a random 0X address using solidity. It would be the best if it could be an existing address, however, I understand that it might be too complicated to do (it might need an ...
0
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1answer
18 views

Is it possible to create a trigger when a state variable contract is i.e. 10?

Let's supose this is my contract: Contract MyContract{ uint a = 0; function myFunction(){ a = 0; } } I want "myFunction" to fire up when "a" value is 10. Thanks.
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0answers
14 views

I can see my ethereum but its not going to my wallet

My ethereum has been confirmed delivered but not in my wallet,fairly new but I have made successful transactions before,I can see my ethereum in etherscan.io 0x2ecc74c6e9c42eea14863fbc1e1d9656b339a6ec ...
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0answers
14 views

Custom token showing balance of 0 in MyEtherWallet

I made a new token on the Ropsten test network. Here's the contract address: 0x801fd9c17087ec868dc8540055b7ea3cb6dbbe34. When I followed the instructions to add this custom token to MyEtherWallet (by ...
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0answers
17 views

Custom allowance for metamask

I want to customizing my allowance for a token in Metamask, but I'm in trouble about which tool I have to use.. Is smart contract obligatory for custom allowance? Or I can do with just Javascript? ...
0
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0answers
16 views

How to enable and use the accounting module?

I found the accounting module in this line and want to use them. i attached the accounting module to parameter --rpcapi accounting when run console node but could not found this module. run node: ....
0
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1answer
16 views

error: VM Exception while processing transaction: revert SafeMath: subtraction overflow on migrating crowdsale conract

I am developing the token sale Dapp using openzepplin-solidity version 2.3. While migrating, I got the following error. Returned error: VM Exception while processing transaction: revert SafeMath:...
0
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1answer
19 views

Create self-airdrop to 20,000 wallet addresses with specific conditions

I want to create an aidrop to my ERC20 token with automatic distribution: -The user must therefore send 0 ETH to the smart contract or to a specific address, and he will automatically receive his ...
0
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1answer
16 views

Tallying Majority Consensus From Nested Struct

How do I tally the votes of a nested struct to find out majority consensus? as an example, if we have following scenario below; I want to create a function which allows me to calculate whether ...
0
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1answer
16 views

What is the best combination of transactions to send to an Address for a given target amount?

Let's suppose I have 100 unlocked accounts with different balances and I want to have in a target account an amount X. Knowing that I have to make an individual transaction for every account, what ...
0
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0answers
18 views

What is meant by Ethereum instrumentation?

Some body please tell me what is meant by Ethereum instrumentation? I found this term in following two articles at: [EVM* From Offline Detection to Online Reinforcement for Ethereum Virtual Machine1 ...
0
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1answer
15 views

How can i make payment application using the blockchain?

i want to make payment based application by scratch using blockchain, so where can i learn from scratch and what are the different component that i should learn to make an application or a website ...
0
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0answers
6 views

HyperLedger Mobile Application Development

For market reasons I am studying the HyperLedger platform. In the last year I studied the Ethereum platform where I developed web/mobile applications. My question regarding HyperLedger Fabric is: On ...
1
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1answer
16 views

Upgradability Proxy ADMIN_SLOT assembly sstore does not update

I'm currently playing around with Proxy Upgradability, and noticed the use of assembly in terms of the new upgraded contract and the slot assigned. Real implementation can be seen here. I have ...
0
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0answers
24 views

Interaction smart contract and third-party app : How to make sure the request comes from the original contract?

I'm working on a blockchain project where I need to access data stored outside the smart contract. The smart contract own a RSA keypair (one public and one private key). We want the private key to ...
-2
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0answers
31 views

My vote Count is not updating (https://github.com/llSourcell/Your_First_Decentralized_Application) i'm trying this project

Total vote is not increamenting, code link web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545")); abi = JSON.parse('[{"constant":false,"inputs":[{"name":"candidate","type":"...
0
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1answer
18 views

Private transaction validation in quorum

I was going through the quorum documentation and stumbled upon how private transactions are validated in quorum. Take the following example where there are four nodes - Node A, Node B, Node C and Node ...
3
votes
2answers
113 views

Inline assembly, good or bad practice

I often see inline assembly in Solidity contracts. I consider this a bad practice because of the poor readability, however this is my opinion only and there must be valid reasons to use it. There are ...
0
votes
1answer
30 views

I am getting error while installing truffle in Ubuntu 16.04 LTS. How to resolve this issue?

When i enter this command: sudo npm install -g truffle I get the following error: > truffle@5.0.27 postinstall /usr/lib/node_modules/truffle > node ./scripts/postinstall.js Error: EACCES: ...
1
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0answers
13 views

I can not get to my MEW using Ledger Nano S

When I want to open my wallet using ledger, it says that "No Compatible devices were found"( it is just in Slovak language), however my ledger works as I am using it with another wallets. It only ...
2
votes
2answers
26 views

Transaction disappeared from the pending transactions in node

My ether wallet has been working for more than 1 year. Today There was a memory issue in my node and the node shutdown. When I restarted the node via geth client the node resound ~5000 blocks behind ...
0
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2answers
44 views

How to create a RawTransaction for contract interaction Web3j

I want to sign a transaction that calls a smart contract function and send it to the Rinkeby network. I found on Web3j documentation the RawTransaction class that supports the methods for the ...
0
votes
1answer
20 views

Initialising Empty Arrays & Structs In Struct-based Storage Graph Structures?

How do I initialise empty arrays and structs in nested structs data structures? contract NewBook { struct ReviewerData { string name, uint industryXP // ...
2
votes
1answer
25 views

How make Ethereum QR-code with Input Data?

how i can make QR code with address, amount, gas price and Input Data? Is it possible?
0
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1answer
30 views

How to use window function in controller (node.js)?

So this is my users controller to upload a file : exports.postUploadFile = (req, res, next) => { var ethereumURI = req.body.ethereumURI; var abi = JSON.parse(req.body.abi); var ...
0
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2answers
15 views

it'll give me a parser error

pragma solidity ^0.5.0; contract fisrtCoin { address deployer; mapping(address=>uint) balances; public function fisrtcoin() { deployer = msg.sender; } public ...
0
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0answers
14 views

Why can’t light nodes broadcast transactions directly?

Everything I’ve read about Ethereum thus far seems to state that light nodes are incapable of broadcasting/relaying/etc. transactions themselves. It is also my understanding that light nodes have ...
2
votes
1answer
30 views

How to detect coin transfer from transaction

This is my transaction data. How to detect transfer coin from it (eth, bee, binance coin,...). Thanks. { "status": 200, "title": "OK", "description": "Successful request", "payload": { "...
1
vote
1answer
31 views

Updating an instance of an already stored struct?

How can I update/change the values of a stored struct instance? as an example: Let's say I've already deployed a chapter with the content written in a particular color. Later it turns out that I ...
0
votes
1answer
17 views

Returning an array of inner structs of a struct

How can I return an array of child structs of a parent struct? as an example: After pushing multiple chapters into the parent struct, how can I retrieve all the child structs as an array (or ...
0
votes
0answers
28 views

web3.eth.getAccounts() returns empty array

I'm trying to get accounts like that: window.web3.eth.getAccounts( (error, accounts) => { console.log(accounts, error) } ); but it keeps returning an empty array. I'm running Ganache and I can ...
0
votes
0answers
15 views

Block-chain data retrieval

I'm using a testrpc to test my sensor contract, where many account get to submit data to the block-chain whether using an html client side application or using the smart contract is self. How can I ...
0
votes
1answer
23 views

How does a transaction verified with Truffle test?

I'm a new to Ethereum and Solidity, and I don't understand how Truffle executes transaction calls. From what I learned and understood, if I try to use a contract method which changes the contract's ...
0
votes
1answer
22 views

Connecting my Golang Backend server with Metamask

I'm trying to build a Ticket-Office project in one of my courses at the University. The project uses a backend server (which I'm writing in Golang) and it should be able to deploy and use smart ...
1
vote
1answer
13 views

How to replace Metamask Pop-Up with my own UI

I was wondering if I can replace the Metamask pop-up with my own pop-up/user interface. Example: Currently on my dApp a user clicks "Buy Token" and a Metamask modal pops up and says the usual ...
0
votes
0answers
24 views

solidity-Please help me understand this Smart Contract. Transferring money between adresses in solidity

Hi guys so I have found this code online of a goods and service type contract, where f.e. a digital asset is created and each time that asset is used by someone, beneficiers involved in the "creation" ...
0
votes
1answer
29 views

contract reading array from other contract

There are two contracts in my project: admin groups voting Admin groups contain mapping(uint => address[]) internal m_Admins For example [1][0] = admin #1 with level 1 [9][0] = admin #2 with ...
1
vote
1answer
10 views

Creating an ERC20 Token on Rinkeby - Can't get the right supply

I'm creating an ERC20 token on Remix and using EIP20.sol from Consensys. I'm using this video tutorial as a guide - https://www.youtube.com/watch?v=d5EipPVafsA It's been helpful, however I have one ...
0
votes
0answers
18 views

Smart-contracts referencing each other [duplicate]

How would one retrieve these three addresses in the "Knot" smart-contract? I am very new to this, and would like to know whether this is even possible. The "Knot" contract should be able to reference ...
0
votes
1answer
49 views

Failed to load events from Block 0 on page refresh in Vue app

I'm trying to get event data from the web3 API using events method. In my Vue app methods, I have a method, newDsoValue, that will watch for the events from the beginning and also for every newly ...
0
votes
1answer
12 views

Cannot install remix-ide locally

How to install remix-ide npm module? I follow the instructions, but it does not install. npm install remix-ide -g ... make: *** [Release/obj.target/scrypt/src/node-boilerplate/scrypt_params_async.o] ...
-2
votes
1answer
24 views

TypeError: No matching declaration found after argument-dependent lookup

ERROR:TypeError: No matching declaration found after argument-dependent lookup.require (positionIsInBounds(xpos,ypos)); ^-----^ pragma solidity ^0.5.1; contract TicTacToe { //addresses of ...

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