Array.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.26;

contract Array {
    // Several ways to initialize an array
    uint256[] public arr;
    uint256[] public arr2 = [1, 2, 3];
    // Fixed sized array, all elements initialize to 0
    uint256[10] public myFixedSizeArr;

    function get(uint256 i) public view returns (uint256) {
        return arr[i];
    }

    // Solidity can return the entire array.
    // But this function should be avoided for
    // arrays that can grow indefinitely in length.
    function getArr() public view returns (uint256[] memory) {
        return arr;
    }

    function push(uint256 i) public {
        // Append to array
        // This will increase the array length by 1.
        arr.push(i);
    }

    function pop() public {
        // Remove last element from array
        // This will decrease the array length by 1
        arr.pop();
    }

    function getLength() public view returns (uint256) {
        return arr.length;
    }

    function remove(uint256 index) public {
        // Delete does not change the array length.
        // It resets the value at index to it's default value,
        // in this case 0
        delete arr[index];
    }

    function examples() external pure {
        // create array in memory, only fixed size can be created
        uint256[] memory a = new uint256[](5);

        // create a nested array in memory
        // b = [[1, 2, 3], [4, 5, 6]]
        uint256[][] memory b = new uint256[][](2);
        for (uint256 i = 0; i < b.length; i++) {
            b[i] = new uint256[](3);
        }
        b[0][0] = 1;
        b[0][1] = 2;
        b[0][2] = 3;
        b[1][0] = 4;
        b[1][1] = 5;
        b[1][2] = 6;
    }
}