Functional Programming Concepts in JS

FP encourages pure functions, immutability, and higher‑order functions.

• map, filter, reduce – already covered.
• Immutability – use Object.freeze, spread ({...obj}), or libraries like Immer.
• Currying – turning a function with multiple arguments into a chain of single‑argument functions.

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Example: Simple curry

const add = a => b => a + b;
const add5 = add(5);
console.log(add5(2)); // 7