Is Is Object Empty easy or hard?

Is Object Empty is classified as an Easy problem. It tests familiarity with basic object operations, iteration, and built-in language utilities rather than complex algorithms.

Is Object Empty Python/Java solution

In Python, you can check emptiness using len(obj) == 0 for dictionaries or lists. In Java, checking map.isEmpty() or collection.isEmpty() achieves the same goal. The underlying complexity remains O(n) in the worst case depending on implementation details.

How to solve Is Object Empty in O(n)?

Iterate over the object's keys and determine whether any element exists. Using Object.keys(obj).length === 0 or a for...in loop both work. The algorithm scans the properties once, resulting in O(n) time and O(1) extra space.

What is the best approach for Is Object Empty?

The most common approach checks the number of keys using a built-in helper such as Object.keys(obj).length in JavaScript. If the length is zero, the object is empty. This runs in O(n) time because all keys may be scanned, with O(1) additional space. It is concise and widely expected in interviews.

Is Is Object Empty asked at Google/Amazon/Meta?

Object and dictionary inspection problems appear frequently in interviews at companies like Google, Amazon, and Meta, especially in JavaScript-focused roles. While this exact problem may vary, checking whether a structure contains elements is a common fundamental task.

What data structure is used in Is Object Empty?

The problem operates on objects or associative containers, similar to hash maps or dictionaries. These structures store key-value pairs and allow iteration over keys to determine whether any entries exist.

What is the time complexity of Is Object Empty?

The time complexity is O(n), where n is the number of keys or elements in the object or array. Methods like Object.keys() or iteration loops may need to inspect every property in the worst case. Space complexity is typically O(1) excluding temporary structures created by built-in helpers.

Description Solution Video 9:48

2727. Is Object Empty

Easy80.8% acceptance1 company

Given an object or an array, return if it is empty.

An empty object contains no key-value pairs.
An empty array contains no elements.

You may assume the object or array is the output of JSON.parse.

Example 1:

Input: obj = {"x": 5, "y": 42}
Output: false
Explanation: The object has 2 key-value pairs so it is not empty.

Example 2:

Input: obj = {}
Output: true
Explanation: The object doesn't have any key-value pairs so it is empty.

Example 3:

Input: obj = [null, false, 0]
Output: false
Explanation: The array has 3 elements so it is not empty.

Constraints:

obj is a valid JSON object or array
2 <= JSON.stringify(obj).length <= 10⁵

Can you solve it in O(1) time?

Asked at 1 company

Google

9:48

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

Open solution

LanguageLoading editor…

1/**
2 * @param {Object|Array} obj
3 * @return {boolean}
4 */
5var isEmpty = function(obj) {
6    
7};

Starter codeJavaScriptSpaces: 4

Examples

Case 1Case 2Case 3

Input

{"x": 5, "y": 42}

Input

{}

Input

[null, false, 0]

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