ETH Price: $2,673.24 (+1.36%)

Token

Community Chain (COMC)
 

Overview

Max Total Supply

2,000,000,000 COMC

Holders

20,457

Market

Onchain Market Cap

$0.00

Circulating Supply Market Cap

-

Other Info

Token Contract (WITH 18 Decimals)

Filtered by Token Holder
ZB.com 5
Balance
21,373,935.8532 COMC

Value
$0.00
0xc97a4ed29f03fd549c4ae79086673523122d2bc5
Loading...
Loading
Loading...
Loading
Loading...
Loading

Click here to update the token information / general information
# Exchange Pair Price  24H Volume % Volume

Contract Source Code Verified (Exact Match)

Contract Name:
MyAdvancedToken

Compiler Version
v0.4.24+commit.e67f0147

Optimization Enabled:
Yes with 200 runs

Other Settings:
default evmVersion
/**
 *Submitted for verification at Etherscan.io on 2018-08-02
*/

pragma solidity ^0.4.16;

library SafeMath {

  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
      return 0;
    }
    uint256 c = a * b;
    assert(c / a == b);
    return c;
  }

  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}

contract owned {
    address public owner;

    constructor() public {
        owner = msg.sender;
    }

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

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

contract TokenERC20 {
    using SafeMath for uint256;
    
    // 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);
    // 
    event Approval(address indexed owner, address indexed spender, 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
     */
    constructor(
        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;
        emit 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 returns (bool success) {
        _transfer(msg.sender, _to, _value);
        return true;
    }

    /**
     * Transfer tokens from other address
     *
     * Send `_value` tokens to `_to` in 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 in 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) {
        require((_value == 0) || (allowance[msg.sender][_spender] == 0));
        allowance[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        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
        totalSupply = totalSupply.sub(_value);
        emit 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
        totalSupply = totalSupply.sub(_value);
        emit Burn(_from, _value);
        return true;
    }
}

/******************************************/
/*       ADVANCED TOKEN STARTS HERE       */
/******************************************/

contract MyAdvancedToken is owned, TokenERC20 {

    /*
    uint256 public sellPrice;
    uint256 public buyPrice;
    */

    mapping (address => bool) public frozenAccount;

    /* This generates a public event on the blockchain that will notify clients */
    event FrozenFunds(address target, bool frozen);

    /* Initializes contract with initial supply tokens to the creator of the contract */
    constructor(
        uint256 initialSupply,
        string tokenName,
        string tokenSymbol
    ) TokenERC20(initialSupply, tokenName, tokenSymbol) public {}

    /* Internal transfer, only can be called by this contract */
    function _transfer(address _from, address _to, uint _value) internal {
        require (_to != 0x0);                               // Prevent transfer to 0x0 address. Use burn() instead
        require (balanceOf[_from] >= _value);               // Check if the sender has enough
        require (balanceOf[_to] + _value >= balanceOf[_to]); // Check for overflows
        require(!frozenAccount[_from]);                     // Check if sender is frozen
        require(!frozenAccount[_to]);                       // Check if recipient is frozen
        balanceOf[_from] -= _value;                         // Subtract from the sender
        balanceOf[_to] += _value;                           // Add the same to the recipient
        emit Transfer(_from, _to, _value);
    }

    /// @notice `freeze? Prevent | Allow` `target` from sending & receiving tokens
    /// @param target Address to be frozen
    /// @param freeze either to freeze it or not
    function freezeAccount(address target, bool freeze) onlyOwner public {
        frozenAccount[target] = freeze;
        emit FrozenFunds(target, freeze);
    }
}

Contract Security Audit

Contract ABI

[{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"name":"approve","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_value","type":"uint256"}],"name":"burn","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_value","type":"uint256"}],"name":"burnFrom","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"frozenAccount","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"},{"name":"","type":"address"}],"name":"allowance","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"target","type":"address"},{"name":"freeze","type":"bool"}],"name":"freezeAccount","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"initialSupply","type":"uint256"},{"name":"tokenName","type":"string"},{"name":"tokenSymbol","type":"string"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"name":"target","type":"address"},{"indexed":false,"name":"frozen","type":"bool"}],"name":"FrozenFunds","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Burn","type":"event"}]

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

Deployed Bytecode

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

Constructor Arguments (ABI-Encoded and is the last bytes of the Contract Creation Code above)

0000000000000000000000000000000000000000000000000000000077359400000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000000a0000000000000000000000000000000000000000000000000000000000000000f436f6d6d756e69747920436861696e00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000004434f4d4300000000000000000000000000000000000000000000000000000000

-----Decoded View---------------
Arg [0] : initialSupply (uint256): 2000000000
Arg [1] : tokenName (string): Community Chain
Arg [2] : tokenSymbol (string): COMC

-----Encoded View---------------
7 Constructor Arguments found :
Arg [0] : 0000000000000000000000000000000000000000000000000000000077359400
Arg [1] : 0000000000000000000000000000000000000000000000000000000000000060
Arg [2] : 00000000000000000000000000000000000000000000000000000000000000a0
Arg [3] : 000000000000000000000000000000000000000000000000000000000000000f
Arg [4] : 436f6d6d756e69747920436861696e0000000000000000000000000000000000
Arg [5] : 0000000000000000000000000000000000000000000000000000000000000004
Arg [6] : 434f4d4300000000000000000000000000000000000000000000000000000000


Swarm Source

bzzr://ca77735677ede803475ef9c870fdfe4d01e90c6394f344158c3fd2878af06902
Loading...
Loading
Loading...
Loading
[ Download: CSV Export  ]
[ Download: CSV Export  ]

A token is a representation of an on-chain or off-chain asset. The token page shows information such as price, total supply, holders, transfers and social links. Learn more about this page in our Knowledge Base.