Is To Be Or Not To Be easy or hard?

LeetCode classifies this problem as Easy with an acceptance rate around 62%. The difficulty comes from understanding closures or designing a small assertion-style API rather than implementing a complex algorithm.

To Be Or Not To Be Python/Java solution

In Python, the solution can mimic the closure pattern by returning an object or nested functions that capture the value. In Java, C++, and C#, the typical approach is a class with methods toBe and notToBe that operate on a stored instance variable.

How to solve To Be Or Not To Be in O(1)?

Store the initial value when expect(val) is called. Then implement two methods: toBe(val2) and notToBe(val2). Each method performs a constant-time comparison and either returns true or throws an error if the assertion fails.

What is the best approach for To Be Or Not To Be?

The closure-based approach is the most common solution, especially in JavaScript. It captures the input value inside the expect function and returns methods that compare against it. Both toBe and notToBe run in O(1) time with O(1) space because they only perform a constant-time equality check.

Is To Be Or Not To Be asked at Google/Amazon/Meta?

The problem style appears in frontend or JavaScript-focused interview rounds where understanding closures and API design is tested. Similar assertion utility questions are common in interviews at companies that emphasize JavaScript fundamentals.

What data structure is used in To Be Or Not To Be?

No complex data structure is required. The solution relies on either a closure that stores a single value or a class object containing that value as a field. The logic is built around simple equality checks.

What is the time complexity of To Be Or Not To Be?

All valid implementations run in O(1) time because the solution only performs a single equality comparison between two values. Space complexity is also O(1) since only one value is stored either in a closure or as a class field.

Description Solution Video 5:58

2704. To Be Or Not To Be

Easy62.6% acceptance6 companies

Write a function expect that helps developers test their code. It should take in any value val and return an object with the following two functions.

toBe(val) accepts another value and returns true if the two values === each other. If they are not equal, it should throw an error "Not Equal".
notToBe(val) accepts another value and returns true if the two values !== each other. If they are equal, it should throw an error "Equal".

Example 1:

Input: func = () => expect(5).toBe(5)
Output: {"value": true}
Explanation: 5 === 5 so this expression returns true.

Example 2:

Input: func = () => expect(5).toBe(null)
Output: {"error": "Not Equal"}
Explanation: 5 !== null so this expression throw the error "Not Equal".

Example 3:

Input: func = () => expect(5).notToBe(null)
Output: {"value": true}
Explanation: 5 !== null so this expression returns true.

Asked at 6 companies

Adobe Microsoft

Google Amazon Meta Bloomberg

5:58

Still stuck?Read 3 approaches, or watch a walkthrough.

Open solution

LanguageLoading editor…

1/**
2 * @param {string} val
3 * @return {Object}
4 */
5var expect = function(val) {
6    
7};
8 
9/**
10 * expect(5).toBe(5); // true
11 * expect(5).notToBe(5); // throws "Equal"
12 */

Starter codeJavaScriptSpaces: 4

Examples

Case 1Case 2Case 3

Input

() => expect(5).toBe(5)

Input

() => expect(5).toBe(null)

Input

() => expect(5).notToBe(null)

Your code is saved on this device.Solution