nodlAndHodl

pragma solidity ^0.4.24;

contract Fundraiser {
    mapping(address=>uint) balances;

    // VULNERABLE
    function withdrawCoins(){
        uint withdrawAmount = balances[msg.sender];
        Wallet wallet = Wallet(msg.sender);
        wallet.payout.value(withdrawAmount)();

nodlAndHodl

// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

contract LemonadeStand {

    address owner; 
    uint skuCount;
    
    enum State { ForSale , Sold, Shipped }
    

nodlAndHodl

// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;

contract myToken {

    string public constant name = "Tokenomics";
    string public constant symbol = "TOK";
    uint8 public constant decimals = 18;  // 18 is the most common number of decimal places
    uint _totalSupply;

nodlAndHodl

// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;

contract EventsContract {
    // Represents the time when the bidding will end
    uint biddingEnds = block.timestamp + 5 days;

    struct HighestBidder {
        address bidder;
        string bidderName;

nodlAndHodl

// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;

contract MainContract {

    uint public value;

    constructor (uint amount) {
        value = amount;
    }

nodlAndHodl

pragma solidity >=0.7.0 <0.9.0;

contract Modifiers2 {

    uint  public  minimumOffer = 100;

    modifier  minimumAmount(){
        //Could also use require( msg.value >= minimumOffer)
        if(msg.value >= minimumOffer){
            _;

nodlAndHodl

pragma solidity >=0.8.10;

contract FunctionsContract {

    string ownerName;
    uint8  ownerAge;

    // Constructor
    constructor (string memory name, uint8 age) public {
        ownerName = name;

nodlAndHodl

pragma solidity >=0.4.24;

contract GlobalVariables {

    string  public lastCaller = "not-set";

    // Demonstrates the use of the ether subdenominations
    function etherUnitsTest() public pure returns(bool) {
        // True
        bool value = (1 ether == 1000 finney);

nodlAndHodl

pragma solidity >=0.4.22 <0.9.0;

contract StringConversion {

    function getStringElementAtIndex(uint index, string memory myString) public pure returns (byte){
            bytes memory stringToBytes = bytes(myString);
            return stringToBytes[index];
    }
}

nodlAndHodl

Solidity Notes

Solidity has basic structure like so

Contracts

contract NewContract {
  uint data; // contract fields like this are in storage
  
constructor(uint _data) public {