These are chat archives for ethereum/tutorials

Aug 2017
Brooks Boyd
Aug 30 2017 01:16
If you follow the ERC20 standard, it has a name and symbol that client applications know to look for to draw those UI elements
Aug 30 2017 01:18
@MidnightLightning Thanks! :)
Aug 30 2017 02:57
mapping (address => mapping (address => uint256)) public allowance........what does this line of code mean?
Thanks GUYS!!!
Aug 30 2017 04:35
Anyone tell me one thing , I want to create a coin for commercial purpose . There are three pages in the tutorial . If I implement all three of them, what other things I need to do in order to create a whole new coin like (lite coin or ether )
Aug 30 2017 04:41
Will this be sufficient to create the full network . I mean do I need to do something else before getting it commercial
Aug 30 2017 07:44
Hello everyone
can anyone tell me how to buy etherum with usd
any contract is available to buy ETH ??
Brooks Boyd
Aug 30 2017 11:23
@Jpeng0108 It's a mapping that contains another mapping in each of it's slots (nested map)
@vishwas96 Yes, that's all that's needed. Ethereum is the network under it, so you don't need to build that part
@ashishjiet you can buy ETH with USD via exchanges: Coinbase, Kraken, etc.
Aug 30 2017 14:19
@MidnightLightning Thankyou for answering. Like in bitcoin, a coin is generated when someone does the mining. How will i do that is it given in the tutorials?
Brooks Boyd
Aug 30 2017 14:23
If you want your token/coin to be mined as a separate entity, yes you'd need to implement the mining logic. Or, because Ether is already a mined currency available to all smart contracts on Ethereum, you can use that infrastructure and tell your users to mine/acquire Ether, and then your coin/token only needs to offer a means to trade Ether for some quantity of your token.
Aug 30 2017 14:56
Ok thank you very much .Really appreciate your help
I will work on my own mining logic.
Aug 30 2017 15:57
Hello, I am new to the Ether, can anyone help me out to get started
Brooks Boyd
Aug 30 2017 16:05
@seidelion is a good place to start, which has descriptions and tutorials to work on.
Aug 30 2017 16:11
Thank you, how do I get to the first tutorial, what is the best strategy to start with?
Aug 30 2017 18:28
Can someone please give me a way to start and what this is all about
Help please
Brooks Boyd
Aug 30 2017 18:32
Just go to and read down; the first tutorial is there under the 'Issue your token' button.
Are you looking for a general description of what Ethereum is, or help getting started as a developer in Ethereum?
Aug 30 2017 18:36
I would like both, as well as a few other concepts
I am a new developer, many ideas but need to understand the framework, and how to earn
Dane Lowrey
Aug 30 2017 21:25
I just started through the tutorials, can someone tell me if I am correct? Ethereum contracts are essentially just programs on a decentralized blockchain that get executed by 'miners' who then get to keep a fee for executing the program?
Brooks Boyd
Aug 30 2017 22:03
The last part of that is mostly true: The smart contracts are instructions, which first miners just store on the blockchain (developer pays a transaction fee for it to be included in the blockchain). Then any user can request those instructions be triggered (send a transaction that names a function they want executed), and then they pay for the executing of that function (to the miners). So, there's two steps, first create/store the contract on the decentralized blockchain, and then a separate transaction to execute it.
Aug 30 2017 22:27
Algum desenvolvedor brasileiro por aqui?
Preciso contratar consultoria...
@MidnightLightning codes are not compiling do you have any other tutorial for crowdfunding
Aug 30 2017 22:39
@MidnightLightning follow the code, it's the tutorial code just fixing the throw issue...

pragma solidity ^0.4.2;

contract owned {
address public owner;

function owned() {
    owner = msg.sender;

modifier onlyOwner {
    require (msg.sender == owner);

function transferOwnership(address newOwner) onlyOwner {
    owner = newOwner;


contract tokenRecipient {
event receivedEther(address sender, uint amount);
event receivedTokens(address _from, uint256 _value, address _token, bytes _extraData);

function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData){
    Token t = Token(_token);
    require (!t.transferFrom(_from, this, _value));
    receivedTokens(_from, _value, _token, _extraData);

function () payable {
    receivedEther(msg.sender, msg.value);


contract Token {
mapping (address => uint256) public balanceOf;
function transferFrom(address _from, address _to, uint256 _value) returns (bool success);

/ The shareholder association contract itself /

contract Association is owned, tokenRecipient {

/* Contract Variables and events */
uint public minimumQuorum;
uint public debatingPeriodInMinutes;
Proposal[] public proposals;
uint public numProposals;
Token public sharesTokenAddress;

event ProposalAdded(uint proposalID, address recipient, uint amount, string description);
event Voted(uint proposalID, bool position, address voter);
event ProposalTallied(uint proposalID, uint result, uint quorum, bool active);
event ChangeOfRules(uint newMinimumQuorum, uint newDebatingPeriodInMinutes, address newSharesTokenAddress);

struct Proposal {
    address recipient;
    uint amount;
    string description;
    uint votingDeadline;
    bool executed;
    bool proposalPassed;
    uint numberOfVotes;
    bytes32 proposalHash;
    Vote[] votes;
    mapping (address => bool) voted;

struct Vote {
    bool inSupport;
    address voter;

/* modifier that allows only shareholders to vote and create new proposals */
modifier onlyShareholders {
    require (sharesTokenAddress.balanceOf(msg.sender) > 0);

/* First time setup */
function Association(Token sharesAddress, uint minimumSharesToPassAVote, uint minutesForDebate) payable {
    changeVotingRules(sharesAddress, minimumSharesToPassAVote, minutesForDebate);

/// @notice Make so that proposals need tobe discussed for at least `minutesForDebate/60` hours and all voters combined must own more than `minimumSharesToPassAVote` shares of token `sharesAddress` to be executed
/// @param sharesAddress token address
/// @param minimumSharesToPassAVote proposal can vote only if the sum of shares held by all voters exceed this number      
/// @param minutesForDebate the minimum amount of delay between when a proposal is made and when it can be executed    
function changeVotingRules(Token sharesAddress, uint minimumSharesToPassAVote, uint minutesForDebate) onlyOwner {
    sharesTokenAddress = Token(sharesAddress);
    if (minimumSharesToPassAVote == 0 ) minimumSharesToPassAVote = 1;
    minimumQuorum = minimumSharesToPassAVote;
    debatingPeriodInMinutes = minutesForDebate;
    ChangeOfRules(minimumQuorum, debatingPeriodInMinutes, sharesTokenAddress);

/// @notice Propose to send `weiAmount / 1E18` ether to `beneficiary` for `JobDescription`. `transactionBytecode ? Contains : Does not contain` code.
/// @param beneficiary who to send the ether to      
/// @param weiAmount amount of ether to send, in wei       
/// @param JobDescription Description of job
/// @param transactionBytecode bytecode of transaction
function newProposal(
    address beneficiary,
    uint weiAmount,
    string JobDescription,
    bytes transactionBytecode
    returns (uint proposalID)
    proposalID = proposals.length++;
    Proposal storage p = proposals[proposalID];
Aug 30 2017 23:10
Hello i want ask one information about etherium wallet software