_You can follow along with the video course from here._ ### Introduction You can find the code for this section in the [Remix Storage Factory Github repository](https://github.com/cyfrin/remix-storage-factory-f23). In these nine lessons, we'll work with three new contracts: 1. `SimpleStorage.sol` - the contract we build in the previous section, with some modifications 2. `AddFiveStorage.sol` - a child contract of `SimpleStorage` that leverages _inheritance_ 3. `StorageFactory.sol` - a contract that will _deploy_ a `SimpleStorage` contract and _interact_ with it ### Section overview ```solidity contract SimpleStorage { SimpleStorage[] public listOfSimpleStorageContracts; function createSimpleStorageContract() public {}; function sfStore(uint256 _simpleStorageIndex, uint256 _simpleStorageNumber) public {}; function sfGet(uint256 _simpleStorageIndex) public view returns (uint256) {} } ``` After deploying `StorageFactory` and executing its function `createSimpleStorageContract`, we can observe a new transaction appear in the Remix terminal. It's a **deployment transaction** of the `SimpleStorage` contract, executed by the `StorageFactory` contract. It's possible to interact with this newly deployed `SimpleStorage` via the `store` function. We'll do this by using the **`sfStore`** function from the `StorageFactory` contract. This function accepts two parameters: the index of a deployed `SimpleStorage` contract, which will be '0' since we just deployed one contract, and the value of a `favoriteNumber`. The **`sfGet`** function, when given the input '0', will indeed return the number provided by the previous function. The **address** of the `SimpleStorage` contract can then be retrieved by clicking on the get function `listOfSimpleStorageContracts`. ### Conclusion The `StorageFactory` contract manages numerous instances of an external contract `SimpleStorage`. It provides functionality to deploy new contract instances dynamically and allows for the storage and retrieval of values from each instance. These instances are maintained and organized within an array, enabling efficient tracking and interaction. ### 🧑‍💻 Test yourself 1. 📕 What is the primary role of the `StorageFactory` contract? 2. 📕 Why is it important to specify the index when calling the `sfStore` function?