• There are two type of arrays:

1. Fixed Sized Array:

• The size of an array is defined at the creation of the array
• cannot be resized after creation of array
• e.g

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

contract FixedSizedArray {
	uint[3] nums;
	
	function add(uint _num1, uint _num2, uint _num3) public {
		nums[0] = _num1;       
		nums[1] = _num2;       
		nums[2] = _num3;   
	}     
	
	function search(uint _index) public view returns (uint) {       
	  require(_index < 3, "this is a 3 indexed fixed array");       
	  return nums[_index];   
	}
  
	function array() public view returns (uint256[3] memory){       
    return nums;   
   }
   
}

2. Dynamic Array:

• The sized of array is dynamic i.e it can be changed dynamically at execution time.
• e.g

contract DynamicArray{

	uint[] nums;
	
	function addNumber(uint _num) public {
		nums.push(_num);
	}
	
	function getCount() public view returns (uint){
		return nums.length;
	}
	
	function getNumAtIndex(uint _index) public view returns (uint){
		return nums[_index];
	}
	
	function getNums() public view returns (uint[] memory){
	 return nums;
	}

}