Stack overflow concept in Javascript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a function that calls itself.

Javascript

function recurse() {
  console.log('Hello');
  [1]();
}
recurse();

Drag options to blanks, or click blank then click option'

Arecurse

Bconsole

Clog

Dcall

Attempts:

3 left

💡 Hint

Common Mistakes

Using console or log instead of the function name.

Trying to call a method that doesn't exist.

The function calls itself by its name recurse(), which is how recursion works.

2fill in blank

medium

Complete the code to add a base case that stops recursion when n is 0.

Javascript

function countdown(n) {
  if (n [1] 0) {
    return;
  }
  console.log(n);
  countdown(n - 1);
}
countdown(3);

Drag options to blanks, or click blank then click option'

A==

B>

C<

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using > or < instead of ==, which leads to incorrect output.

Using != which does not stop at zero.

The base case checks if n == 0 to stop the recursion.

3fill in blank

hard

Fix the error in the recursive function to avoid infinite recursion.

Javascript

function sum(n) {
  if (n <= 0) {
    return 0;
  }
  return n + sum([1]);
}
console.log(sum(3));

Drag options to blanks, or click blank then click option'

An

Bn - 1

Cn + 1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Adding 1 to n causes infinite recursion.

Passing n unchanged causes infinite recursion.

To reduce n each time and reach the base case, we call sum(n - 1).

4fill in blank

hard

Fill both blanks to create a recursive factorial function with a base case.

Javascript

function factorial(n) {
  if (n [1] 1) {
    return 1;
  }
  return n * factorial([2]);
}
console.log(factorial(4));

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A<=

B-1

Cn - 1

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using == in base case but not handling n=0 properly.

Using -1 instead of n - 1 in recursive call.

The base case stops when n is less or equal to 1, and the recursive call uses n - 1.

5fill in blank

hard

Fill all three blanks to create a recursive function that counts down and stops at zero.

Javascript

function countDown(n) {
  if (n [1] 0) {
    return;
  }
  console.log([2]);
  countDown([3]);
}
countDown(3);

Drag options to blanks, or click blank then click option'

A==

Bn

Cn - 1

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using == instead of > in base case returns immediately without printing numbers.

Printing n - 1 instead of n.

Calling countDown with n instead of n - 1.

The base case checks if n is greater than zero, prints n, then calls countDown with n - 1.