Contract Source Code:
File 1 of 1 : TokenERC20
pragma solidity ^0.4.16;
interface tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData) public; }
contract TokenERC20 {
// Public variables of the token
string public name;
string public symbol;
uint8 public decimals = 18; // 18 decimals is the strongly suggested default, avoid changing it
uint256 public totalSupply; // This creates an array with all balances
mapping (address => uint256) public balanceOf;
mapping (address => mapping (address => uint256)) public allowance;
// This generates a public event on the blockchain that will notify clients
event Transfer(address indexed from, address indexed to, uint256 value);
// This notifies clients about the amount burnt
event Burn(address indexed from, uint256 value);
/** * Constrctor function * * Initializes contract with initial supply tokens to the creator of the contract */
function TokenERC20( uint256 initialSupply, string tokenName, string tokenSymbol ) public
{ totalSupply = initialSupply * 10 ** uint256(decimals);
// Update total supply with the decimal amount
balanceOf[msg.sender] = totalSupply;
// Give the creator all initial tokens
name = tokenName;
// Set the name for display purposes
symbol = tokenSymbol; // Set the symbol for display purposes
}
/** * Internal transfer, only can be called by this contract */
function _transfer(address _from, address _to, uint _value) internal {
// Prevent transfer to 0x0 address. Use burn() instead
require(_to != 0x0);
// Check if the sender has enough
require(balanceOf[_from] >= _value);
// Check for overflows
require(balanceOf[_to] + _value > balanceOf[_to]);
// Save this for an assertion in the future
uint previousBalances = balanceOf[_from] + balanceOf[_to];
// Subtract from the sender
balanceOf[_from] -= _value;
// Add the same to the recipient
balanceOf[_to] += _value; Transfer(_from, _to, _value);
// Asserts are used to use static analysis to find bugs in your code. They should never fail
assert(balanceOf[_from] + balanceOf[_to] == previousBalances); }
/** * Transfer tokens * * Send `_value` tokens to `_to` from your account * * @param _to The address of the recipient * @param _value the amount to send */
function transfer(address _to, uint256 _value) public { _transfer(msg.sender, _to, _value); }
/** * Transfer tokens from other address * * Send `_value` tokens to `_to` on behalf of `_from` * * @param _from The address of the sender * @param _to The address of the recipient * @param _value the amount to send */
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) { require(_value <= allowance[_from][msg.sender]);
// Check allowance
allowance[_from][msg.sender] -= _value;
_transfer(_from, _to, _value); return true; }
/** * Set allowance for other address * * Allows `_spender` to spend no more than `_value` tokens on your behalf * * @param _spender The address authorized to spend * @param _value the max amount they can spend */
function approve(address _spender, uint256 _value) public returns (bool success) { allowance[msg.sender][_spender] = _value; return true; }
/** * Set allowance for other address and notify * * Allows `_spender` to spend no more than `_value` tokens on your behalf, and then ping the contract about it * * @param _spender The address authorized to spend * @param _value the max amount they can spend * @param _extraData some extra information to send to the approved contract */
function approveAndCall(address _spender, uint256 _value, bytes _extraData) public returns (bool success) { tokenRecipient spender = tokenRecipient(_spender); if (approve(_spender, _value)) { spender.receiveApproval(msg.sender, _value, this, _extraData); return true; } }
/** * Destroy tokens * * Remove `_value` tokens from the system irreversibly * * @param _value the amount of money to burn */
function burn(uint256 _value) public returns (bool success) { require(balanceOf[msg.sender] >= _value);
// Check if the sender has enough
balanceOf[msg.sender] -= _value;
// Subtract from the sender
totalSupply -= _value;
// Updates totalSupply
Burn(msg.sender, _value); return true; }
/** * Destroy tokens from other account * * Remove `_value` tokens from the system irreversibly on behalf of `_from`. * * @param _from the address of the sender * @param _value the amount of money to burn */
function burnFrom(address _from, uint256 _value) public returns (bool success) { require(balanceOf[_from] >= _value);
// Check if the targeted balance is enough
require(_value <= allowance[_from][msg.sender]);
// Check allowance
balanceOf[_from] -= _value;
// Subtract from the targeted balance
allowance[_from][msg.sender] -= _value;
// Subtract from the sender's allowance
totalSupply -= _value;
// Update totalSupply
Burn(_from, _value); return true; } }