Benchmark: isEmptyObject: keys vs for in 2.1

Script Preparation code:

function keys(obj) {
    if (!obj) {
        return [];
    }
    if (Object.keys) {
        return Object.keys(obj);
    }
    var keyList = [];
    for (var key in obj) {
        if (obj.hasOwnProperty(key)) {
            keyList.push(key);
        }
    }
    return keyList;
}

function isEmptyObj(obj) {
    return !keys(obj).length;
}

function isEmptyObj2(obj) {
    if (!obj) {
        return true;
    }
    for (var key in obj) {
        if (obj.hasOwnProperty(key)) {
            return false;
        }
    }
    return true;
}

var testObj = {
    "siteId": "81ac2a67a958e7aebff3df41ee9797a9"
}

Tests:

keys
isEmptyObj(testObj)
for in
isEmptyObj2(testObj)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
keys
for in

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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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 definition and explain what's being tested.

**Overview**

The benchmark measures the performance of two different approaches to check if an object is empty: using the `for...in` loop (`keys`) versus directly checking the length of the object (`isEmptyObj2`).

**Test Cases**

There are two individual test cases:

1. **keys**: This test case uses the `keys` function, which checks if an object has any properties by iterating over it with a `for...in` loop. If no properties exist, it returns an empty array.
2. **for in**: This test case uses the `isEmptyObj2` function, which checks if an object is empty by iterating over its properties using a `for...in` loop. If no properties exist, it returns `true`.

**Options Compared**

The two options being compared are:

* Using a `for...in` loop to check if an object has any properties (`keys`)
* Directly checking the length of an object to determine if it's empty (`isEmptyObj2`)

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

**Keys (for...in loop)**

Pros:

* Can handle cases where the object has non-enumerable properties
* More flexible, as it can be used to check if an object has any properties, regardless of their type

Cons:

* Can be slower due to the overhead of iterating over properties
* May not perform well on very large objects or those with many properties

**isEmptyObj2 (Direct Length Check)**

Pros:

* Generally faster than using a `for...in` loop, as it only requires a single operation
* More memory-efficient, as it doesn't require creating an array to store property names

Cons:

* Only works for objects that have enumerable properties
* May not work correctly if the object has non-enumerable properties or other edge cases

**Library: Lodash**

The `keys` function is likely a custom implementation of the Lodash `keys()` function, which checks if an object has any properties and returns them as an array.

In this benchmark, both functions are using a similar approach to check for emptiness: iterating over the object's properties. However, they differ in their implementation details and performance characteristics.

**Special JS Features/Syntax**

None of the test cases use any special JavaScript features or syntax that would affect their performance or behavior.

**Alternatives**

If you're looking for alternative ways to check if an object is empty, here are a few options:

* Using `Object.keys(obj).length === 0` ( direct length check, similar to `isEmptyObj2`)
* Using `for...in` loop with `hasOwnProperty()` (similar to `keys`, but without the need to store property names in an array)
* Using `Object.getOwnPropertyNames()` and checking its length (another alternative to `keys`)

Keep in mind that these alternatives may have slightly different performance characteristics or edge cases compared to the original implementation.

Related benchmarks:

isEmptyObject: keys vs for in 2.1 (version: 0)

Comparing performance of: keys vs for in

Created: 4 years ago by: Guest

Jump to the latest result

keys

for in

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):