Token Creation
Create your own token
What Is ERC-20?
One of the most significant Ethereum tokens is known as ERC-20. ERC-20 has emerged as the technical standard; it is used for all smart contracts on the Ethereum blockchain for token implementation and provides a list of rules that all Ethereum-based tokens must follow.
ERC-20 is similar, in some respects, to bitcoin, Litecoin, and any other cryptocurrency; ERC-20 tokens are blockchain-based assets that have value and can be sent and received. The primary difference is that instead of running on their own blockchain, ERC-20 tokens are issued on the Ethereum network.
QRX-20 / ERC-20 Token Contract example
This example shows how to create your own token on the Questos network. It is an example of a QRX-20 (ERC-20) token only.
pragma solidity ^0.4.8; // ERC Token Standard #20 Interface // https://github.com/ethereum/EIPs/issues/20 contract ERC20Interface { // Get the total token supply function totalSupply() constant returns (uint256 totalSupply); // Get the account balance of another account with address _owner function balanceOf(address _owner) constant returns (uint256 balance); // Send _value amount of tokens to address _to function transfer(address _to, uint256 _value) returns (bool success); // Send _value amount of tokens from address _from to address _to function transferFrom(address _from, address _to, uint256 _value) returns (bool success); // Allow _spender to withdraw from your account, multiple times, up to the _value amount. // If this function is called again it overwrites the current allowance with _value. // this function is required for some DEX functionality function approve(address _spender, uint256 _value) returns (bool success); // Returns the amount which _spender is still allowed to withdraw from _owner function allowance(address _owner, address _spender) constant returns (uint256 remaining); // Triggered when tokens are transferred. event Transfer(address indexed _from, address indexed _to, uint256 _value); // Triggered whenever approve(address _spender, uint256 _value) is called. event Approval(address indexed _owner, address indexed _spender, uint256 _value); } contract FixedSupplyToken is ERC20Interface { string public constant symbol = "FIXED"; string public constant name = "Example Fixed Supply Token"; uint8 public constant decimals = 18; uint256 _totalSupply = 1000000; // Owner of this contract address public owner; // Balances for each account mapping(address => uint256) balances; // Owner of account approves the transfer of an amount to another account mapping(address => mapping (address => uint256)) allowed; // Functions with this modifier can only be executed by the owner modifier onlyOwner() { if (msg.sender != owner) { throw; } _; } // Constructor function FixedSupplyToken() { owner = msg.sender; balances[owner] = _totalSupply; } function totalSupply() constant returns (uint256 totalSupply) { totalSupply = _totalSupply; } // What is the balance of a particular account? function balanceOf(address _owner) constant returns (uint256 balance) { return balances[_owner]; } // Transfer the balance from owner's account to another account function transfer(address _to, uint256 _amount) returns (bool success) { if (balances[msg.sender] >= _amount && _amount > 0 && balances[_to] + _amount > balances[_to]) { balances[msg.sender] -= _amount; balances[_to] += _amount; Transfer(msg.sender, _to, _amount); return true; } else { return false; } } // Send _value amount of tokens from address _from to address _to // The transferFrom method is used for a withdraw workflow, allowing contracts to send // tokens on your behalf, for example to "deposit" to a contract address and/or to charge // fees in sub-currencies; the command should fail unless the _from account has // deliberately authorized the sender of the message via some mechanism; we propose // these standardized APIs for approval: function transferFrom( address _from, address _to, uint256 _amount ) returns (bool success) { if (balances[_from] >= _amount && allowed[_from][msg.sender] >= _amount && _amount > 0 && balances[_to] + _amount > balances[_to]) { balances[_from] -= _amount; allowed[_from][msg.sender] -= _amount; balances[_to] += _amount; Transfer(_from, _to, _amount); return true; } else { return false; } } // Allow _spender to withdraw from your account, multiple times, up to the _value amount. // If this function is called again it overwrites the current allowance with _value. function approve(address _spender, uint256 _amount) returns (bool success) { allowed[msg.sender][_spender] = _amount; Approval(msg.sender, _spender, _amount); return true; } function allowance(address _owner, address _spender) constant returns (uint256 remaining) { return allowed[_owner][_spender]; } }