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44

Put simply, sidechaining is any mechanism that allows tokens from one blockchain to be securely used within a completely separate blockchain but still moved back to the original chain if necessary. By convention the original chain is normally referred to as the "main chain", while any additional blockchains which allow users to transact within them in the ...


44

3 Primary improvements with ERC223 Eliminates the problem of lost tokens which happens during the transfer of ERC20 tokens to a contract (when people mistakenly use the instructions for sending tokens to a wallet). ERC223 allows users to send their tokens to either wallet or contract with the same function transfer, thereby eliminating the potential for ...


36

Update Mar 29 2017 The latest instructions can be found at The DAO Refunds. Notes This Withdrawal contract only allows the conversion of The DAO tokens (DAO) into ethers (ETH) at the rate of 100 DAOs = 1 ETH. The way the Withdrawal contract has been coded means that you HAVE to approve the transfer of ALL DAOs in your account, as the Withdrawal contract ...


20

Thank you K.Fichter for the help, I just want to fully clarify the answer for anyone else who may run into this issue. Let's say you want to get the balance of a token at an Ethereum Address. Using Web3 you would do the following: var tokenContract = web3.eth.contract(contractABI).at(contractAddress) var decimal = tokenContract.decimals() var balance = ...


18

Hypothetically speaking, yes. If someone managed to guess a private key to 0x0, then they would have full control over all ether/tokens belonging to that address. It is so unlikely that it's considered impossible because you would have to randomly generate private keys until you found one that generates the 0x0 address. Also, there might not even be a ...


16

It is not really true at the moment that you can pay fees in anything except ETH, although there is some discussion about changing this. The way things normally work, you have to pay the fee in ETH. When you sent REP to the exchange you probably used ETH in your own account to deposit tokens in the exchange, and the exchange would have paid for the ...


14

Sidechain is a blockchain that runs in parallel to the main blockchain which extends functionality through interoperable blockchain networks allowing a decentralized way of transferring/synchronizing your tokens between the two chains. In other words, you can move your cryptocurrency to the sidechain and then back to the main chain. Sidechains are ...


13

Update Apr 12 2017 There are only 3 more days to withdraw your refunds from the WhitehatWithdraw contract. There are still 1,651,062.7506 ETC (USD 4,292,763.15) remaining in the withdrawal contract. 87% of accounts have NOT withdrawn their refunds. Check this spreadsheet to confirm that you have withdrawn all your refunds. Following is a chart of the ...


13

I think it has to ultimately be human verification, unless it exactly matches an existing contract that's already been verified by humans. Even if all the functions that are supposed to be in the standard are there and do what they're supposed to, you can't be sure that somebody hasn't done something unexpected in a different part of the code. It's probably ...


13

At a high level, the main parts of ERC20 specify: 1. how tokens can be transferred by its owner 2. how tokens can be transferred on behalf of an owner 3. how to get data about the token 4. events about the token The first specifies the obvious requirement that tokens must be transferrable, and what ERC20 defines is that you would tell the token contract ...


12

According to Jeff Wilcke, the right way to burn ETH is to create a contract which immediately self destructs and sends to its own address, or just send ether to his deployed contract which does it all for you: https://etherscan.io/address/0xb69fba56b2e67e7dda61c8aa057886a8d1468575#code Here's the code: pragma solidity ^0.4.11; contract Burner { ...


12

You need to give Metamask the address of the token itself, not the address of the contract that created the token, like you did. I made the same mistake myself.


11

Update Mar 29 2017 The latest instructions can be found at The DAO Refunds. At the hard-fork block #1,920,000 , the ETH balance from The DAO and it's child DAOs (which includes the balance from the extraBalance account) were transferred into the Withdrawal contract. Immediately after the hard-fork, at block #1,920,090, the Withdrawal contact's ...


11

Thanks for asking, this is a common question but did not have a good public answer. I've updated the MetaMask user FAQ to include a response, and am copying that answer here: MetaMask does not currently display your token balances, but that doesn't mean you can't manage your tokens with MetaMask! Since MetaMask allows any website to interact with the ...


11

How about using Etherscan's Event Log API? https://api.etherscan.io/api?module=logs&action=getLogs &fromBlock=0 &toBlock=latest &address=[Token Contract Address] &topic0=0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef &topic1=[From Address, padded to 32 bytes - optional] &topic2=[To ...


11

There could be any number of ERC20 contracts deployed with the name string variable "Golem Network Token." However, each one of these contracts has a unique Ethereum contract address. The ERC20 contract address deployed by Golem is 0xa74476443119A942dE498590Fe1f2454d7D4aC0d. If someone else deployed a clone contract it would have a different address and ...


11

It wasn't just just "someone"... it was the contract creator who made the transaction, and there is a function called mintTokens which allows them to exactly do this. /** * Allows owner to create tokens without ETH */ function mintTokens(address _address, uint256 amount) public onlyOwner isUnderHardCap { if(disown == 1) revert(); if (amount + ...


10

There are 2 ways using https://etherscan.io/ : Navigate to https://etherscan.io/ . Enter the account in the search box on the top right, the click Go. If there are tokens associated with the account, you will see the Token Tracker dropdow. Clicking this will show you the number of tokens owned by the account. For example: https://etherscan.io/address/...


9

Remove Greyed Out Token While you can hover your mouse over active Tokens and click on the trashcan icon to delete it, you will have to manually remove greyed out tokens. In the Ethereum Wallet (Mist) menu, click on Develop -> Toggle Developer Tools -> Wallet UI. Alternatively, if you're using Parity (in your web browser), open up that browser's Developer ...


9

After the creation period ends on May 28th, you will be able to send DAO Tokens, similar to how you send ETH. You can send your entire amount of DAO Tokens or just a portion of them. It should be noted that with The DAO Tokens specifically, you cannot send the tokens if they are currently "tied up" in a vote. This prevents a single token from voting more ...


9

The way I think about this is that the number of tokens is: tokenSupply = tokensIActuallyWant * (10 ^ decimals) If I want 1 token with the ability to subdivide it with a precision of 2 decimal places, I represent that as 100. Similarly if I want 1 token with the ability to subdivide that to 18 decimal places, I need to represent that as ...


9

throw was deprecated in solidity version 0.4.13. You need to replace each line that says if(condition) throw; with require(opposite of condition);. For example: if (_to == 0x0) throw; becomes require(_to != 0x0); throw is used a number of times throughout your code, you need to change every one


9

It is not possible as on 24th March 2018. Etherscan is unable to locate contract code on the address of subcontract. Here is the transaction which deploys two contracts. But for the second contract, etherscan is unable to find contract code. The second contract does exist and this was verified by using "at address" feature of remix. Until there are some ...


8

Yes. Here Is theDAOVoter Description theDAOVoter v1.0000000000000003 is a little Perl script (~808 lines, 738 source lines) that will allow you to: List The DAO proposals. List your accounts, displaying whether The DAO transfers are blocked due to opened votes and expiry time. List the DAO proposals with a listing of your accounts showing which accounts ...


8

Interface contracts work like other interface agreements in traditional object oriented languages. In your example, the interface specifies the functions a contract of type TokenInterface must implement to fit into the overall application framework. This allows you to customize code without having to implement everything from scratch. For example, in ...


8

What is actually happening in sub-dividable token contracts (and ETH itself) is that the actual unit is tiny. Really, really tiny. A single ether is actually just 10^18 wei. For the sake of the users, it's shown on the various frontends as a decimal number of ETH. The same principle applies in token contracts. Internally it's just a standard uint holding ...


8

MetaMask does not have a default UI for sending tokens yet. The official guide lists three current web interfaces that can be used for sending tokens, but none are provided as a default because they do not all necessarily work with all tokens. Using the wallet.ethereum.org interface, you should be able to manage tokens easily enough. A default 'send' page ...


8

Ether itself has 18 decimals, most ERC-20 tokens simply follow that standard. 1 ETH is represented by 10^18 of its natural unit ( 1 Ether = 1,000,000,000,000,000,000 wei ). This offers you much greater precision - essentially, you aren't limited to trading the equivalent of a cent ($0.01 for example), you can go much, much lower. It means you can own - ...


7

I'm surprised about the confusion, or more the underlying lack of transparency, surrounding this very basic functionality. It's somewhat strange that the 'experts' haven't been communicative about this matter. There are two ways: Just transfer your DAO Tokens to an exchange and sell them. Choose the long and winding route of splitting into your own DAO and ...


7

The JAXX wallet has just entered its iOS Beta. Source.


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