MulArray.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @title Array Multiplication.
 * @author [Anthony (fps)](https://github.com/fps8k)
 * @dev Contract to demonstrate how an array is multiplied.
 */

contract MulArray {
    /**
     * @dev Takes in an array of numbers and adds them and returns the cumultative product.
     * @param _arr array of numbers
     * @return product which is the cumultative product of the array.
     */
    function mulArr(uint256[] memory _arr)
        public
        pure
        returns (uint256 product)
    {
        /// @dev Initialize the total we need to return to 0.
        uint256 _product = 1;

        /// @dev Loop through the array.
        for (uint256 i = 0; i < _arr.length; i++) {
            /// @dev On every element, multiply the current _product with the value of the elementa.
            /// @dev For products > the maximum uint value, solidity versions > 0.8.0 will revert on overflow.
            _product *= _arr[i];
        }

        /// @dev Return the product.
        product = _product;
    }
}