Recursion Base Case and Recursive Case in DSA Typescript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the base case in recursion?

The base case is the condition that stops the recursion. It prevents infinite calls by returning a simple, direct answer.

beginner

What is the recursive case in recursion?

The recursive case is where the function calls itself with a smaller or simpler input, moving towards the base case.

intermediate

Why do we need both base case and recursive case in a recursive function?

The base case stops the recursion to avoid infinite loops, and the recursive case breaks the problem into smaller parts to solve it step by step.

beginner

In the factorial function, what is the base case and what is the recursive case?<br><pre>function factorial(n: number): number { if (n === 0) return 1; return n * factorial(n - 1); }</pre>

Base case: when n === 0, return 1.<br>Recursive case: return n * factorial(n - 1), calling itself with smaller n.

beginner

What happens if a recursive function has no base case?

The function will keep calling itself forever, causing a stack overflow error because it never stops.

What does the base case in recursion do?

A Creates a loop

B Calls the function again

C Increases the input size

D Stops the recursion

The base case stops the recursion by providing a direct answer.

Which part of recursion calls the function itself?

A Recursive case

B Base case

C Loop case

D Exit case

The recursive case calls the function itself with a smaller input.

What will happen if a recursive function lacks a base case?

A It will return zero

B It will stop immediately

C It will run forever causing an error

D It will run once

Without a base case, recursion never stops and causes a stack overflow error.

In the factorial function, what is the base case?

A n === 0

B n === 1

C n > 0

D n < 0

The base case for factorial is when n equals 0, returning 1.

Why is the recursive case important?

A It stops the recursion

B It breaks the problem into smaller parts

C It increases the problem size

D It returns the final answer

The recursive case breaks the problem into smaller parts to solve it step by step.

Explain the roles of the base case and recursive case in a recursive function.

Think about how recursion stops and how it continues.

Describe what happens when a recursive function is missing a base case.

What happens if the function never stops calling itself?