Instruction: Explain how TypeScript supports or enhances Functional Programming concepts with examples.
Context: This question explores the candidate's ability to apply Functional Programming principles in TypeScript, leveraging its type system and features to write pure and side-effect-free code.
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Firstly, TypeScript's type system is instrumental in ensuring function purity and preventing side effects—a core tenet of Functional Programming. By explicitly defining function return types and parameter types, TypeScript allows developers to predict and enforce the kind of operations a function can perform, ensuring that functions have no hidden behaviors related to state or I/O and that their outputs are solely determined by their inputs. For example, consider a function that calculates the total price of an order:
function calculateTotal(orderItems: { price: number; quantity: number }[]): number { return orderItems.reduce((total, item) => total + item.price * item.quantity, 0); }...