智能合约测试例子

// SPDX-License-Identifier: MIT
pragma solidity >=0.4.11 <0.9.0;
contract CrowdFunding {
    // 定义的新类型包含两个属性。
    struct Funder {
        address addr;
        uint amount;
    }

    struct Campaign {
        address payable  beneficiary;
        uint fundingGoal;
        uint numFunders;
        uint amount;
        mapping (uint => Funder) funders;
    }

    uint numCampaigns;
    mapping (uint => Campaign)   campaigns;

    function newCampaign(address beneficiary, uint goal) public  returns (uint ) {
       uint campaignID = numCampaigns++; 

         Campaign storage c = campaigns[campaignID];
       c.beneficiary=payable(beneficiary);
       c.fundingGoal=goal;
       c.amount=0;
       c.numFunders=0;
       return campaignID;
    }

    function contribute(uint campaignID) public payable   {

        
        Campaign storage c = campaigns[campaignID];
       
        c.funders[c.numFunders++] = Funder({addr: msg.sender, amount: msg.value});
        c.amount += msg.value;

    }

    function checkGoalReached(uint campaignID) public    returns (bool reached) {
        Campaign storage c = campaigns[campaignID];
        if (c.amount < c.fundingGoal)
            return false;
        uint amount = c.amount;
        c.amount = 0;
        c.beneficiary.transfer(amount);
        return true;
    }
    function info(uint campaignID) public view returns(uint){
        Campaign storage c = campaigns[campaignID];
         uint amount = c.amount;
         return amount;
    }
}

Remix - Ethereum IDE