Contract Source Code (Solidity)

IDE

• Blockscan IDE
• 🤖 Code ReaderBeta
• Remix IDE

Outline

library SafeMath    - function mul(uint256 a, uint256 b)    - function div(uint256 a, uint256 b)    - function sub(uint256 a, uint256 b)    - function add(uint256 a, uint256 b)  contract ERC20    - function balanceOf(address who)    - function transfer(address to, uint256 ...    - function allowance(address owner, add ...    - function transferFrom(address from, a ...    - function approve(address spender, uin ...  contract BasicToken is ERC20    - function transfer(address _to, uint25 ...    - function balanceOf(address _owner)  contract StandardToken is ERC20, B ...    - function transferFrom(address _from, ...    - function approve(address _spender, ui ...    - function allowance(address _owner, ad ...  contract MetaGraphChain is Standar ... *    - function MetaGraphChain(address _owne ...    - function changeName(string _name)    - function changeSymbol(string _symbol)    - function changeNameAndSymbol(string _ ...

More Options

• Similar
• Sol2Uml
• Submit Audit
• Compare

/**
 *Submitted for verification at Etherscan.io on 2018-02-28
*/

pragma solidity ^0.4.18;


/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a * b;
        assert(a == 0 || 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;
    }
}
 
/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 {
    uint256 public totalSupply;
    function balanceOf(address who) public constant returns (uint256);
    function transfer(address to, uint256 value) public returns (bool);
    function allowance(address owner, address spender) public constant returns (uint256);
    function transferFrom(address from, address to, uint256 value) public returns (bool);
    function approve(address spender, uint256 value) public returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20 {
    using SafeMath for uint256;

    mapping(address => uint256) balances;

    /**
    * @dev transfer token for a specified address
    * @param _to The address to transfer to.
    * @param _value The amount to be transferred.
    */
    function transfer(address _to, uint256 _value) public returns (bool) {
        require(_to != address(0));
        require(_value <= balances[msg.sender]);
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(_value);
        Transfer(msg.sender, _to, _value);
        return true;
    }

    /**
    * @dev Gets the balance of the specified address.
    * @param _owner The address to query the the balance of.
    * @return An uint256 representing the amount owned by the passed address.
    */
    function balanceOf(address _owner) public constant returns (uint256 balance) {
        return balances[_owner];
    }

}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 */
contract StandardToken is ERC20, BasicToken {

    mapping (address => mapping (address => uint256)) allowed;


    /**
     * @dev Transfer tokens from one address to another
     * @param _from address The address which you want to send tokens from
     * @param _to address The address which you want to transfer to
     * @param _value uint256 the amout of tokens to be transfered
     */
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
        require(_to != address(0));
        require(_value <= balances[_from]);
        require(_value <= allowed[_from][msg.sender]);
        var _allowance = allowed[_from][msg.sender];

        // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
        // require (_value <= _allowance);

        balances[_to] = balances[_to].add(_value);
        balances[_from] = balances[_from].sub(_value);
        allowed[_from][msg.sender] = _allowance.sub(_value);
        Transfer(_from, _to, _value);
        return true;
    }

    /**
     * @dev Aprove the passed address to spend the specified amount of tokens on behalf of msg.sender.
     * @param _spender The address which will spend the funds.
     * @param _value The amount of tokens to be spent.
     */
    function approve(address _spender, uint256 _value) public returns (bool) {

        // To change the approve amount you first have to reduce the addresses`
        //  allowance to zero by calling `approve(_spender, 0)` if it is not
        //  already 0 to mitigate the race condition described here:
        //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
        require((_value == 0) || (allowed[msg.sender][_spender] == 0));

        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }

    /**
     * @dev Function to check the amount of tokens that an owner allowed to a spender.
     * @param _owner address The address which owns the funds.
     * @param _spender address The address which will spend the funds.
     * @return A uint256 specifing the amount of tokens still avaible for the spender.
     */
    function allowance(address _owner, address _spender) public view returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }

}

/**
 * @title MetaGraphChain is Standard ERC20 token
 */
contract MetaGraphChain is StandardToken {

    string public name = "MetaGraphChain";
    string public symbol = "BKBT";
    address owner;
    uint public decimals = 18;
    uint public INITIAL_SUPPLY = 10000000000*10**18;

    function MetaGraphChain(address _owner) public {
        owner = _owner;
        totalSupply = INITIAL_SUPPLY;
        balances[msg.sender] = 1000*10**18;
        balances[_owner] = INITIAL_SUPPLY - 1000*10**18;
    }

    function changeName(string _name) public {
        if (msg.sender == owner)
            name = _name;
    } 

    function changeSymbol(string _symbol) public {
        if (msg.sender == owner)
            symbol = _symbol;
    } 
 
    function changeNameAndSymbol(string _name,string _symbol) public {
        if (msg.sender == owner) { 
            name = _name;
            symbol = _symbol;
        }
    } 
}

• No Contract Security Audit Submitted- Submit Audit Here

[{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_name","type":"string"},{"name":"_symbol","type":"string"}],"name":"changeNameAndSymbol","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"name":"approve","outputs":[{"name":"","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":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"INITIAL_SUPPLY","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_name","type":"string"}],"name":"changeName","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"balance","type":"uint256"}],"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":"_symbol","type":"string"}],"name":"changeSymbol","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"}],"name":"allowance","outputs":[{"name":"remaining","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[{"name":"_owner","type":"address"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"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"}]

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

000000000000000000000000606a324bbabf1c9deafbb8e90f22ee588a08599c

-----Decoded View---------------
Arg [0] : _owner (address): 0x606A324BbAbF1C9DEAFbb8E90F22eE588a08599c

-----Encoded View---------------
1 Constructor Arguments found :
Arg [0] : 000000000000000000000000606a324bbabf1c9deafbb8e90f22ee588a08599c

bzzr://e9c8d7ea0ecde7a401dcfa017638e84c2d66d8393d5ce38d58084b921d4d2f73