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Lesson 5:
 Variables
Introduction to Solidity variables
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Variables
There are 3 types of variables in Solidity:
- State Variables
- Declared outside of functions
 - Stored on the blockchain
 
 - Local Variables
- Declared inside functions
 - Not stored on the blockchain
 
 - Global Variables
- Provides information about the blockchain
 
 
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
contract Variables {
    // State variables are stored on the blockchain.
    string public text = "Hello";
    uint256 public num = 123;
    function doSomething() public {
        // Local variables are not saved to the blockchain.
        uint256 i = 456;
        // Here are some global variables
        uint256 timestamp = block.timestamp; // Current block timestamp
        address sender = msg.sender; // address of the caller
    }
}