JS Practice — Built-in Objects

Function.length — rest parameters not counted

📖 Usage Example

const arrow = (a, b) => a + b
arrow.length  // → 2

Arrow functions also have a length property reflecting their parameter count.

fn.length — rest params excluded

Rest parameters (...args) are never counted in fn.length. A function with only a rest parameter has length === 0.

Challenge: Verify that ((...args) => {}).length === 0.

💡 Hints (1)