I am kinda new to Solidity.

kindly shed light in below issues:

  1. How to properly enter token quantity in Initial Supply (in this formula) , say it is 10 million

    contract MyCoin is StandardToken {
      string public name = "TOKKA";
      string public symbol = "TOK";
      uint256 public decimals = 18;
      uint256 constant INITIAL_SUPPLY = 1234 * 10**18;
      function StandardToken() public {
        balance[msg.sender] = INITIAL_SUPPLY;
  2. In case of non mintable tokens, why we have mintable term here:

      // creates the token to be sold.
      // override this method to have crowdsale of a specific mintable token.
      function createTokenContract() internal returns (StandardToken) {
          return new MyCoin();
  3. How do you call createContract here? Where it is located?

    address public token;  // <---- contract used in the crowdsale
    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();

    About RUN section of Remix:

  4. InjectedWeb3 - why usually the Address line is empty?

  5. Gas limit - do I need to modify it? If I put 150.000 then all contributors must pay this gas?
  6. Value - wei: what and why I put? sth there?

1 Answer 1


1: It should be 10 million multiplied by the decimals, so:

uint256 constant INITIAL_SUPPLY = 10000000 * 10** uint(decimals);

2: It is unrelated to whether or not the tokens are mintable. The crowdsale contract will deploy a new token contract which -according to your MyCoin definition- sets the initial supply to whatever you defined and assigns that to the creator. IMPORTANT: Notice you are not setting the totalSupply...

3: It is being called by the crowdsale contract's constructor. Deploying the crowdsale will call this function which will create a token contract and assign the crowdsale's token variable to it.

4: If you are using Metamask it shouldn't be empty, it will read the account you have unlocked with Metamask.

5: Not relevant. That is a local thing on Remix allowing you to increase the gas limit.

6: used if you want to execute a payable function and send ether to it.

Not my intention to disrespect you, but given the questions you are asking, I recommend you do some reasearch before trying to deploy an actual crowdsale / token on the mainnet. :)

  • Pablo, thanks for feedback. 3. can you kindly show this part the way it should be? where and what exactly I should provide in here? this is the only part where Remix gives ParserError (indicating 'contract') 4. ok i will try. 5 and 6: as i understand I dont touch them, right?
    – user25297
    Commented Dec 16, 2017 at 1:03
  • There must be a problem with the constructor parameters you are supplying. Look at the first 4 require lines. They state what you should be passing as parameters. Commented Dec 16, 2017 at 1:07

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