what is the difference between hard cap and soft cap in ethereum ICO

Question

Please someone provide me details about the hard cap and soft cap in ICO. I have to build an ICO with an hard cap. How do I implement it in a smart contract using solidity? Provide me concept behind the hard cap so I will implement the same in a smart contract.

Answer 1

A hard cap is defined as the maximum amount a crowdsale will receive. Most projects set a very high cap that is unlikely to happen. Only very famous projects like Status or Brave browser have reached its hard cap.

contract crowdsale {
    uint public maximumEther;
    uint public totalEther;

    function () payable {
        // Do not accept payment if recaudation is above maximumEther
        if (totalEther + msg.value >= maximumEther) throw;

        // Emit tokens
        totalEther = totalEther + msg.value;
    }
}

A soft cap is the amount received at which your crowdsale will be considered a success. It is the minimal amount required by your project.

If you do not reach that amount during the ICO then you will allow the investors to retire their apport.