Benchmark: _.isEmpty vs arr/length

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Script Preparation code:

window.arr = [];

for (var i = 0, len = 100; i < len; i++) {
  window.arr.push('key' + i);
}

Tests:

_.isEmpty
_.isEmpty(window.arr);
arr.length === 0
window.arr.length === 0;
arr.length
!window.arr.length;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_.isEmpty
arr.length === 0
arr.length

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Context**

The test case creates an array `window.arr` with 100 elements, pushes some keys into it, and then uses two different approaches to check if the array is empty: using Lodash's `isEmpty` function (`_.isEmpty(window.arr)`), comparing the length of the array directly (`window.arr.length === 0`), and using a negated comparison (`!window.arr.length`).

**Library: Lodash**

The benchmark uses Lodash, a popular JavaScript utility library. The specific function being tested is `isEmpty`, which checks if an object (in this case, an array) is empty.

**Special JS Feature/Syntax: None**

There are no special JavaScript features or syntax used in the benchmark.

**Approach Comparison**

The two main approaches being compared are:

1. **Lodash's `isEmpty` function**: This function takes an object as input and returns a boolean indicating whether the object is empty.
2. **Direct comparison using `window.arr.length === 0`**: This approach directly compares the length of the array to 0.

**Pros and Cons**

**Lodash's `isEmpty` function:**

Pros:

* Provides a clear and concise way to check if an object is empty
* Can be useful in various scenarios where you need to check for emptiness

Cons:

* May incur additional overhead due to the function call and potentially more complex internal logic
* Not all browsers or environments may support or optimize this function correctly

**Direct comparison using `window.arr.length === 0`**

Pros:

* Typically faster and more lightweight compared to calling a function
* Can be optimized by some browsers or engines for arrays with known sizes

Cons:

* Requires manual handling of array elements, which can lead to errors if not done correctly
* May not work as expected in certain edge cases (e.g., NaN values)

**Other Considerations**

* The use of `window.arr` instead of a local variable might affect performance due to scope resolution and potential hoisting issues.
* The benchmark does not account for the impact of array push order or the distribution of keys on performance.

**Alternatives**

Other approaches to check if an array is empty include:

1. Using `Array.prototype.length === 0` directly, which is similar to the direct comparison approach but uses a more standardized and well-known method.
2. Creating a new array with only one element (an empty array) and comparing the two arrays using `===`.
3. Using bitwise operations or other creative approaches that exploit specific properties of JavaScript arrays.

Keep in mind that these alternatives might not be as straightforward or efficient as the Lodash function or direct comparison approach, but they can provide additional insights into the performance characteristics of different methods.

Related benchmarks:

_.isEmpty vs arr/length (version: 0)

Comparing performance of: _.isEmpty vs arr.length === 0 vs arr.length

Created: 6 years ago by: Guest

Jump to the latest result

_.isEmpty

arr.length === 0

arr.length

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):