Questions about Crowdsale contract

Question

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?

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. :)