Function expressions assign functions to variables, providing flexibility in function creation and enabling conditional function definition. As the creator of CoreUI, a widely used open-source UI library, I’ve used function expressions extensively for dynamic function creation and modular code organization. From my expertise, function expressions are ideal when you need to conditionally create functions or pass them as arguments. This approach offers more control over function scope and timing compared to function declarations.

Arrow functions are a modern ES6 feature that provides a more concise syntax for writing functions, especially useful for callbacks and functional programming. As the creator of CoreUI, a widely used open-source UI library, I’ve used arrow functions extensively throughout the codebase for cleaner and more readable code. From my expertise, arrow functions are perfect for simple operations and callbacks due to their concise syntax and lexical this binding. This approach reduces boilerplate code and improves code readability significantly.