Benchmark: Fastest way to check if an object with potentially lots of data is empty

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

const arr = [];

for(i = 0; i < 10000; i++)
{
    arr.push([`key_${i}`, `val_${i}`]);
}

var obj = Object.fromEntries(arr);

var isObjectEmpty = (objectName) => {
  for (let prop in objectName) {
    if (objectName.hasOwnProperty(prop)) {
      return false;
    }
  }
  return true;
};

Tests:

object.keys()
Object.keys(obj) === 0
JSON.stringify()
JSON.stringify(obj) === "{}"
_.isEmpty()
_.isEmpty(obj) === true
for ... in
isObjectEmpty(obj) === true

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
object.keys()
JSON.stringify()
_.isEmpty()
for ... in

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Measuring the efficiency of different approaches to check if an object is empty involves comparing various methods. Let's break down what's being tested, pros and cons of each approach, and other considerations.

**Benchmarked Methods:**

1.  **`object.keys()`**: This method returns an array of a given object's own enumerable property names.
2.  **`JSON.stringify(obj) === "{}"`**: This checks if the string representation of the object is equal to the empty JSON string, indicating the absence of any properties.
3.  **`.isEmpty()` (from Lodash)**: A utility function that returns `true` if the object has no own enumerable properties and `false` otherwise.
4.  **`for...in` loop**: This method iterates over an object's own enumerable properties using a traditional for loop.

**Pros and Cons of Each Approach:**

1.  **`object.keys()`**:

*   Pros:
        *   Lightweight, as it only returns property names without any additional overhead.
        *   Fast, since it doesn't require creating a new string representation.
    *   Cons:
        *   May not work well for objects with non-enumerable properties or inherited properties.
        *   Can be slower than other methods in modern browsers due to the need to create an array of property names.

2.  **`JSON.stringify(obj) === "{}"`**:

*   Pros:
        *   Portable across different environments, as JSON serialization is a standard format.
        *   Works well with objects that have non-enumerable properties or inherited properties.
    *   Cons:
        *   Can be slower than other methods due to the overhead of creating and serializing the object's contents.
        *   Not suitable for large objects, as it requires allocating memory for the string representation.

3.  **`.isEmpty()` (from Lodash)**:

*   Pros:
        *   Fast and efficient, as it uses a specialized implementation under the hood.
        *   Portable across different environments, including modern browsers.
    *   Cons:
        *   Requires the use of an external library (Lodash).
        *   May not be suitable for very large objects due to potential memory allocation issues.

4.  **`for...in` loop**:

*   Pros:
        *   Lightweight and efficient, as it only iterates over enumerable properties.
        *   Works well with objects that have non-enumerable properties or inherited properties.
    *   Cons:
        *   Can be slower than other methods in modern browsers due to the need to iterate over all enumerable properties.
        *   May require additional checks to account for non-enumerable properties.

**Library Consideration:**

In this benchmark, Lodash's `.isEmpty()` function is used. Lodash provides a set of utility functions and methods for working with JavaScript objects, arrays, and more. The `.isEmpty()` function checks if an object has any own enumerable properties and returns `true` if it does not.

**Special JavaScript Feature:**

There are no special JavaScript features or syntax mentioned in the provided benchmark definition. However, it's worth noting that some JavaScript implementations may optimize certain methods for specific use cases (e.g., `for...in` loop).

**Other Alternatives:**

Some alternative approaches to check if an object is empty include:

*   Using `Object.getOwnPropertyNames()` instead of `Object.keys()`, which returns both enumerable and non-enumerable properties.
*   Implementing a custom function using `hasOwnProperty()` or other methods to check for the presence of specific properties.
*   Using a different approach, such as checking if the object's size is zero (e.g., using `Object.byteLength` on Uint8Array-like objects).

Keep in mind that each alternative approach has its own pros and cons, and some may be more suitable than others depending on the specific use case.

**Benchmark Preparation Code:**

The provided script preparation code creates a large array of objects with keys and values, then creates an object from this array using `Object.fromEntries()`. The script also defines a custom function `isObjectEmpty()` to check if an object is empty by iterating over its properties.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36

Browser/OS: Chrome 118 on Windows

View result in a separate tab

Test name	Executions per second
object.keys()	1197.7 Ops/sec
JSON.stringify()	619.5 Ops/sec
_.isEmpty()	1203.6 Ops/sec
for ... in	1198.1 Ops/sec

Related benchmarks:

Fastest way to check if an object with potentially lots of data is empty (version: 0)

You don't need to make add for loops in your test scenarios, the benchmark does it itself.

Comparing performance of: object.keys() vs JSON.stringify() vs _.isEmpty() vs for ... in

Created: one year ago by: Registered User

Jump to the latest result

object.keys()

JSON.stringify()

_.isEmpty()

for ... in

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):