Solidity-Solidity coding solutions

Example

pragma solidity ^0.8.0; contract SimpleStorage { uint public data; function set(uint x) public { data = x; } function get() public view returns (uint) { return data; }}

Scenario

This basic example illustrates a simple storage contract where a user can store and retrieve an integer value. Such a contract could be a foundational element for more complex applications requiring data persistence, such as a decentralized database.

Example

pragma solidity ^0.8.0; import '@openzeppelin/contracts/token/ERC20/ERC20.sol'; contract MyToken is ERC20 { constructor() ERC20('MyToken', 'MTK') { _mint(msg.sender, 1000 * 10 ** decimals()); }}

Scenario

This example demonstrates the creation of an ERC20 token using the OpenZeppelin library. Tokens are the backbone of many blockchain applications, including ICOs, DeFi platforms, and blockchain-based games. Implementing a token contract can facilitate the creation of a new cryptocurrency, support governance models, or enable asset transfer within a DApp.

Example

pragma solidity ^0.8.0; contract Crowdfunding { address public owner; uint public goal; uint public endTime; mapping(address => uint) public contributions; constructor(uint _goal, uint _duration) { owner = msg.sender; goal = _goal; endTime = block.timestamp + _duration; } function contribute() public payable { require(block.timestamp < endTime, 'Crowdfunding ended'); contributions[msg.sender] += msg.value; } function withdraw() public { require(msg.sender == owner, 'Only owner'); require(block.timestamp > endTime, 'Crowdfunding ongoing'); require(address(this).balance >= goal, 'Goal not met'); payable(owner).transfer(address(this).balance); }}

Scenario

This contract represents a basic crowdfunding campaign where users can contribute funds towards a project goal within a specific timeframe. If the goal is met, the project owner can withdraw the funds; otherwise, contributors can reclaim their contributions. This is useful for fundraising projects, enabling transparency and trust in the collection and allocation of funds.