Benchmark: in check test - MeasureThat.net

Script Preparation code:

window.test = {}
for (i = 0; i < 9999999; i++) {
    test[i] = i
}

window.value = 999999

Tests:

in checking
console.log(value in test)
includes checking
console.log(Object.values(test).includes(value))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
in checking
includes checking

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 dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Definition**

The provided benchmark definition is a JSON object that describes the test case:
```json
{
  "Name": "in check test",
  "Description": null,
  "Script Preparation Code": "window.test = {}\r\nfor (i = 0; i < 9999999; i++) {\r\n    test[i] = i\r\n}\r\n\r\nwindow.value = 999999",
  "Html Preparation Code": null
}
```
Here's what's happening:

1. The script preparation code creates an empty object `test` and populates it with 10 million properties, where each property has a value equal to its key (i.e., `test[i] = i`). This is done using a loop that iterates from 0 to 9999999.
2. It then sets the global variable `window.value` to 999999.

**Options Compared**

The benchmark compares two options:

1. **Direct Check**: `console.log(value in test)`
2. **Indirect Check**: `console.log(Object.values(test).includes(value))`

These two options differ in how they access and verify whether a value exists in the `test` object.

**Pros and Cons**

### Direct Check

Pros:

* Simple and easy to read
* Fast, as it only needs to check if the value is present in the object

Cons:

* Can be slower due to the overhead of using the `in` operator on a large object
* May not work correctly for sparse objects (objects with missing properties)

### Indirect Check

Pros:

* Works correctly for sparse objects, as it checks if the value exists in any of the object's values
* Still relatively fast, as it only needs to check if the value is present in an array of values

Cons:

* More complex and harder to read
* May be slower due to the overhead of creating an array of object values and checking for membership

**Library: Object.values**

The `Object.values` method returns an array of a given object's own enumerable property values. In this case, it's used to get an array of all the values in the `test` object.

**Special JS Feature/Syntax (None)**

There are no special JavaScript features or syntaxes used in this benchmark that would require any particular explanation.

**Other Alternatives**

If you're curious about alternative approaches, here are a few:

1. **Using `Object.prototype.hasOwnProperty.call`**: Instead of checking if a value exists using the `in` operator, you could use `Object.prototype.hasOwnProperty.call` to check if a property is present on an object.
```javascript
console.log(Object.values(test).some(v => v === value) && Object.values(test).some(v => v === value))
```
2. **Using a library like Lodash**: If you need more advanced array manipulation or optimization techniques, you could consider using a library like Lodash.

Keep in mind that these alternatives might not be applicable to this specific benchmark and may have their own trade-offs in terms of performance and complexity.

I hope this explanation helps! Let me know if you have any further questions.

Related benchmarks:

in check test (version: 0)

Comparing performance of: in checking vs includes checking

Created: 4 years ago by: Guest

Jump to the latest result

in checking

includes checking

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):