**Course Title:** Mastering TypeScript: From Basics to Advanced Applications **Section Title:** Introduction to TypeScript and Setup **Topic:** Install TypeScript and write a simple TypeScript program that compiles to JavaScript.(Lab topic) **Objective** By the end of this topic, you will be able to install TypeScript, set up your development environment, and write a simple TypeScript program that compiles to JavaScript. **Prerequisites** Before you begin, ensure you have the following: * Node.js installed on your computer. If not, download and install it from [https://nodejs.org/en/download/](https://nodejs.org/en/download/). * Visual Studio Code (VS Code) installed on your computer. If not, download and install it from [https://code.visualstudio.com/](https://code.visualstudio.com/). * Basic understanding of JavaScript syntax. **Installing TypeScript** To install TypeScript, follow these steps: 1. Open your terminal or command prompt. 2. Install TypeScript globally using the following command: ```bash npm install -g typescript ``` 3. Verify the installation by checking the version of TypeScript: ```bash tsc --version ``` This should display the version of TypeScript installed on your system. **Setting up your Development Environment** Before you start writing TypeScript code, make sure you have the necessary extensions installed in your VS Code: 1. Open VS Code. 2. Navigate to the Extensions view by clicking the Extensions icon in the left sidebar or pressing `Ctrl + Shift + X` (Windows/Linux) or `Cmd + Shift + X` (macOS). 3. Search for "TypeScript" in the Extensions Marketplace. 4. Install the "TypeScript" extension. **Writing a Simple TypeScript Program** Create a new file called `greeter.ts` in your VS Code workspace. Add the following code: ```typescript function greeter(name: string) { console.log(`Hello, ${name}!`); } greeter('Alice'); ``` This program defines a function called `greeter` that takes a `string` parameter `name`. It then logs a greeting message to the console using the `console.log` function. **Compiling the TypeScript Program** To compile the TypeScript program to JavaScript, follow these steps: 1. Open your terminal or command prompt. 2. Navigate to the directory where your `greeter.ts` file is located. 3. Compile the TypeScript program using the following command: ``` tsc greeter.ts ``` This will generate a new file called `greeter.js` in the same directory. **Running the JavaScript Program** To run the compiled JavaScript program, follow these steps: 1. Open your terminal or command prompt. 2. Navigate to the directory where your `greeter.js` file is located. 3. Run the JavaScript program using the following command: ```bash node greeter.js ``` This will execute the program and display the greeting message to the console. **Key Takeaways** * Install TypeScript globally using `npm install -g typescript`. * Verify the installation by checking the version of TypeScript using `tsc --version`. * Set up your development environment by installing the TypeScript extension in VS Code. * Write a simple TypeScript program that defines a function and logs a greeting message to the console. * Compile the TypeScript program to JavaScript using `tsc`. * Run the compiled JavaScript program using `node`. **Exercise** Try modifying the `greeter.ts` program to accept two string parameters, `name` and `greeting`, and log a personalized greeting message to the console. **What's Next?** In the next topic, we will cover conditional statements: if, else, switch. We will explore how to use these statements to control the flow of your program and make decisions based on conditions. **Do You Have Questions or Need Help?** If you have any questions or need help with this topic, feel free to leave a comment below. We'll be happy to assist you.