Notes

Here we introduce you to some primitive data types available in Solidity.

• boolean
• uint256
• int256
• address

solidity
DataTypes.sol
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// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

contract Primitives {
   bool public boo = true;

   /*
   uint stands for unsigned integer, meaning non negative integers
   different sizes are available
       uint8   ranges from 0 to 2 ** 8 - 1
       uint16  ranges from 0 to 2 ** 16 - 1
       ...
       uint256 ranges from 0 to 2 ** 256 - 1
   */
   uint8 public u8 = 1;
   uint public u256 = 456;
   uint public u = 123; // uint is an alias for uint256

   /*
   Negative numbers are allowed for int types.
   Like uint, different ranges are available from int8 to int256
   
   int256 ranges from -2 ** 255 to 2 ** 255 - 1
   int128 ranges from -2 ** 127 to 2 ** 127 - 1
   */
   int8 public i8 = -1;
   int public i256 = 456;
   int public i = -123; // int is same as int256

   // minimum and maximum of int
   int public minInt = type(int).min;
   int public maxInt = type(int).max;

   address public addr = 0xCA35b7d915458EF540aDe6068dFe2F44E8fa733c;

   /*
   In Solidity, the data type byte represent a sequence of bytes. 
   Solidity presents two type of bytes types :

    - fixed-sized byte arrays
    - dynamically-sized byte arrays.
    
    The term bytes in Solidity represents a dynamic array of bytes. 
    It’s a shorthand for byte[] .
   */
   bytes1 a = 0xb5; //  [10110101]
   bytes1 b = 0x56; //  [01010110]

   // Default values
   // Unassigned variables have a default value
   bool public defaultBoo; // false
   uint public defaultUint; // 0
   int public defaultInt; // 0
   address public defaultAddr; // 0x0000000000000000000000000000000000000000
}