Factorial

A Closer Look at Functionseasy

Course · Section 10: A Closer Look at Functions · Lecture 137: First-Class and Higher-Order Functions

Implement `factorial(n)` that returns `n!` (n factorial). Assume `n >= 0`. `factorial(0)` is `1`.

Input: factorial(0)

Output: 1

Input: factorial(1)

Output: 1

Input: factorial(5)

Output: 120

+ 1 hidden test run on Submit.

Common pitfalls

Approach & explanation (try first)

Each call multiplies n by the factorial of n-1, bottoming out at 1.

⌘/Ctrl + Enter

Run your code to see results.

A Closer Look at Functionseasy

Course · Section 10: A Closer Look at Functions · Lecture 137: First-Class and Higher-Order Functions

Implement `factorial(n)` that returns `n!` (n factorial). Assume `n >= 0`. `factorial(0)` is `1`.

Input: factorial(0)

Output: 1

Input: factorial(1)

Output: 1

Input: factorial(5)

Output: 120

+ 1 hidden test run on Submit.

Common pitfalls

Approach & explanation (try first)

Each call multiplies n by the factorial of n-1, bottoming out at 1.

⌘/Ctrl + Enter

Run your code to see results.