I am finalizing this basic but clean Crowdsale code. However, there is ParserError with "contract Cappedcrowdsale". Why? It does refer to Crowdsale though.

Please check if this is a legit Smart Contract code in the end.

pragma solidity ^0.4.17;

contract ERC20Basic {
  uint256 public totalSupply;
  function balanceOf(address who) public view returns (uint256);
  function transfer(address to, uint256 value) public returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);

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 BasicToken is ERC20Basic {
  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]);

    // SafeMath.sub will throw if there is not enough balance.
    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 view returns (uint256 balance) {
    return balances[_owner];


contract ERC20 is ERC20Basic {
  function allowance(address owner, address spender) public view returns (uint256);
  function transferFrom(address from, address to, uint256 value) public returns (bool);
  function approve(address spender, uint256 value) public returns (bool);
  event Approval(address indexed owner, address indexed spender, uint256 value);

contract StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) internal 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 amount of tokens to be transferred
  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]);

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

   * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
   * Beware that changing an allowance with this method brings the risk that someone may use both the old
   * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
   * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   * @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) {
    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 specifying the amount of tokens still available for the spender.
  function allowance(address _owner, address _spender) public view returns (uint256) {
    return allowed[_owner][_spender];

   * approve should be called when allowed[_spender] == 0. To increment
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
  function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
    allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;

  function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
    uint oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue > oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;


contract TOKKA is StandardToken {
    string public name = "TOKKA";
    string public symbol = "TOK";
    uint256 public decimals = 18;

    uint256 constant INITIAL_SUPPLY = 18000000 * 10**18;
    function StandardToken() public {
       balances[msg.sender] = INITIAL_SUPPLY;

contract Crowdsale {
  using SafeMath for uint256;

   // The token being sold
  TOKKA public token;

  // start and end timestamps where investments are allowed (both inclusive)
  uint256 public startTime;
  uint256 public endTime;

  // address where funds are collected
  address public wallet;

  // how many token units a buyer gets per wei
  uint256 public rate;

  // amount of raised money in wei
  uint256 public weiRaised;

  event TokenPurchase(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);

  function Crowdsale(uint256 _startTime, uint256 _endTime, uint256 _rate, address _wallet) public {
    require(_startTime >= now);
    require(_endTime >= _startTime);
    require(_rate > 0);
    require(_wallet != address(0));

    startTime = _startTime;
    endTime = _endTime;
    rate = _rate;
    wallet = _wallet;
    token = createTokenContract();

// creates the token to be sold.
// override this method to have crowdsale of a specific mintable token.
function createTokenContract() internal returns (TOKKA) {
    return new TOKKA();

  // fallback function can be used to buy tokens
  function () external payable {

  // low level token purchase function
function buyTokens(address beneficiary) public payable {
    require(beneficiary != address(0));

    uint256 weiAmount = msg.value;

    // calculate token amount to be created
    uint256 tokens = weiAmount.mul(rate);

    // update state
    weiRaised = weiRaised.add(weiAmount);

    // transfer tokens purchased 
    ERC20(token).transfer(this, tokens);

    TokenPurchase(msg.sender, beneficiary, weiAmount, tokens);


  function forwardFunds() internal {

  function validPurchase() internal view returns (bool) {
    bool withinPeriod = now >= startTime && now <= endTime;
    bool nonZeroPurchase = msg.value != 0;
    return withinPeriod && nonZeroPurchase;

  function hasEnded() public view returns (bool) {
    return now > endTime;

contract CappedCrowdsale is Crowdsale {

  using SafeMath for uint256;

  uint256 public cap;

  function CappedCrowdsale(uint256 _cap) public {
    require(_cap > 0);
    cap = _cap;

  function validPurchase() internal view returns (bool) {
    bool withinCap = weiRaised.add(msg.value) <= cap;
    return super.validPurchase() && withinCap;

  function hasEnded() public view returns (bool) {
    bool capReached = weiRaised >= cap;
    return super.hasEnded() || capReached;


The error is:

ParserError: Function, variable, struct or modifier declaration expected.

You forgot the closing bracket } to end the contract Crowdsale {, so the parser thinks it's still inside a contract when it reaches contract CappedCrowdsale. It's telling you that you can't put a contract (CappedCrowdsale) inside another contract.

  • thanks. I did. Where in the CappedCrowdsale contract I should enter the number of Hard Cap..lets say 2000 ETHs – Buzzmuzz5 Dec 19 '17 at 11:35

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