Benchmark: checks if object has any key - Object.keys vs for key in

Script Preparation code:

const obj = {}
new Array(1000).map((item, index) => {
    obj[index] = index
})

Tests:

Object.keys
const obj = {} new Array(1000).map((item, index) => { obj[index] = index }) return !!Object.keys(obj).length
for key .. in
const obj = {} new Array(1000).map((item, index) => { obj[index] = index }) for(let key in obj){ return true; } return false

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.keys
for key .. in

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided JSON data and explain what is being tested.

**Benchmark Definition**

The benchmark definition represents two different approaches to check if an object has any keys:

1. `Object.keys(obj).length`: This approach uses the built-in `Object.keys()` method to get an array of the object's own enumerable property names, and then checks if the length of that array is greater than 0.
2. `for (let key in obj) { return true; } return false`: This approach uses a traditional `for...in` loop to iterate over the object's properties and checks if any of them are returned.

**Options Compared**

The two options being compared are:

* Using the built-in `Object.keys()` method
* Using a traditional `for...in` loop

**Pros and Cons of Each Approach**

**1. Using `Object.keys()`**

Pros:

* Concise and readable code
* Fast, as it uses optimized C++ code under the hood
* Does not require manual property iteration

Cons:

* May not be supported in older browsers or environments (e.g., IE)
* Can throw an error if the object is not enumerable

**2. Using a `for...in` loop**

Pros:

* Wide browser support, including older versions of Internet Explorer
* No reliance on built-in methods that may have performance issues or security concerns

Cons:

* Longer and more verbose code
* Slower performance compared to using `Object.keys()`
* Requires manual property iteration, which can be error-prone

**Library Usage**

Neither of the provided benchmarks uses a library. However, it's worth noting that some browsers may use internal libraries or optimizations that could affect the results.

**Special JS Feature/Syntax**

There is no special JavaScript feature or syntax being used in these benchmarks. Both approaches are standard JavaScript and do not rely on any advanced features like async/await, callbacks, or closures.

**Other Alternatives**

If you wanted to add more variations to this benchmark, some other options could be:

* Using `for...in` with a `try-catch` block to handle errors
* Using `Object.getOwnPropertyNames()` instead of `Object.keys()`
* Using a library like Lodash or Underscore.js to simplify the code

Keep in mind that the results may vary depending on the specific browser and environment being tested.

Related benchmarks:

checks if object has any key - Object.keys vs for key in (version: 0)

Comparing performance of: Object.keys vs for key .. in

Created: 3 years ago by: Guest

Jump to the latest result

Object.keys

for key .. 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):