Introduction

Etherscan

  • A block explorer analysis tool
  • Lets you view any and all transcations on the blockchain
  • Available for both the mainnet and testnet

Remix

  • A Browser based IDE for Solidity

Primitive Datatypes in Solidity

  • int : integer (signed integer)
  • uint : unsigned integer (uint8, uint16, uint256=unint)
  • bool : Boolean (true or false)
  • address : Ethereum Address

Variables in Solidity

  1. Local Variables

    • Declared inside a function
    • Not stored on the blockchain
  2. State Variables

    • Declared outside a function
    • Stored on the blockchain
  3. Global variables

    • It provides information about the blockchain
    • e.g msg.sender, msg.value, msg.data, block.timestamp

Simple addition program using solidity

pragma solidity ^0.8.0;

contract MyContract {
   unint public number1; //state variable

   function myFunction() public {
      unint num; //local variable
   }

   function newFunction() public return (uint, address) {
      uint num1 = 12;
      uint num2 = 13;
      number1 = num1 + num2;
      address myAddress = msg.sender; //global variable
      return (number1, myAddress); 
   }
}

View and pure

Constructor

Mapping