ArslanKathia

//SPDX-License-Identifier: GPL-3.0

pragma solidity ^0.8.0;
/*
Declare a state variable for setting the maximum number of whitelisted addresses to be allowed.
Use mapping for maintaining a list of addresses and if they are whitelisted or not.
Initialize a maximum number of whitelisting addresses allowed using a constructor.
Write a function to add the address to the whitelist.
Write a function to check if the address is whitelisted or not.
*/

ArslanKathia

//SPDX-License-Identifier: GPL-3.0

pragma solidity >= 0.7.0 < 0.8.18;

/*Set the owner to the deployer of the contract using the constructor.
Use mapping to keep track of each Task.
Write the modifier onlyOwner() so that only the owner can call certain functions.
Adding a new task to the list.
Fetching (Reading) the task from the list.
Mark the task as completed.*/

ArslanKathia

//SPDX-License-Identifier: GPL-3.0

pragma solidity >= 0.7.0 < 0.8.18;

contract Lottery{

    address public manager;
    address payable[] public players;

    constructor(){

ArslanKathia

//SPDX-License-Identifier: MIT

pragma solidity ^0.8;

//solidity cryptographics builtin hash functions
contract HashFun{
    //builtin functions
//keccak256
//hash256
//ripemd160

ArslanKathia

//SPDX-License-Identifier: MIT

pragma solidity ^0.8;

contract DataLocation{
    
    uint[] public arr  = [1,4,5,7,9,10,15];
    //by default state variable store in storage
    function Storage() public {
        uint[] storage arrs = arr;

ArslanKathia

//SPDX-License-Identifier: MIT

pragma solidity ^0.8;


contract Immutable{

    //immutable state variable can be set inline - constructor
    address public immutable owner;
    //constant defined only inline

ArslanKathia

//SPDX-License-Identifier: MIT

pragma solidity ^0.8;

contract SentEther{

    //address payable public getter = payable(0xAb8483F64d9C6d1EcF9b849Ae677dD3315835cb2);

    //add the ether in the smart contract using transact
    receive() external payable{}

ArslanKathia

//SPDX-License-Identifier: MIT

pragma solidity ^0.8;

contract fallback_receive{
   
   event logs(string _msg,address _sender,uint _val,bytes _data);

   //fallback is used to received the data but if received isn't present in contract
   // than fallback handle the received functionality

ArslanKathia

//SPDX-License-Identifier: MIT

pragma solidity ^0.8;

contract Payable{

    // address make it payable
    address payable public owner = payable(msg.sender);

ArslanKathia

//SPDX-License-Identifier: MIT

pragma solidity ^0.8;

contract modifiers{

    address public owner = msg.sender;
    uint public _xx = 10;

    //modifier is used to reuse the same code from the starting or ending of the function