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FunctionalProgrammingadvanced

Pure function composition

📖 Usage Example
const add = a => b => a + b;
const double = x => x * 2;
const addThenDouble = x => double(add(0)(x));
addThenDouble(5); // 10

Pure functions compose cleanly because they're self-contained with no hidden state.

Composing Pure Functions

One benefit of pure functions is that they compose reliably. You can chain them together without worrying about side effects.

Challenge: Compose two pure functions: add(a, b) and double(x). Implement addThenDouble which takes two numbers, adds them, then doubles the result.

💡 Hints (3)
  • • Call add() first with both arguments
  • • Pass the result of add() to double()
  • • Composition of pure functions is also pure