Benchmark: map vs keys - MeasureThat.net

Script Preparation code:

var a=[{x:"a", y:"b"},{x:"a1", y:"b"},{x:"a2", y:"b"},{x:"a3", y:"b"},{x:"a4", y:"b"},{x:"a5", y:"b"},{x:"a6", y:"b"}]
var o={a:"b", a1:"b", a2:"b", a3:"b", a4:"b", a5:"b", a6:"b"}

Tests:

map
a.map(i=>i.x)
keys
Object.keys(o)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
map
keys

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 dive into explaining the provided benchmark.

**Benchmark Definition and Script Preparation Code**

The benchmark is defined in JSON format, which represents two test cases: `map` and `keys`. The script preparation code is a JavaScript snippet that creates an array `a` with 7 objects, each containing `x` and `y` properties. Another object `o` is created, where the keys of `o` are the same as the values in `a`.

**Options being compared**

In this benchmark, two options are compared:

1. **`a.map(i => i.x)`**: This option uses the `map()` method to create a new array with the `x` property of each object in `a`. The `map()` method returns a new array and does not modify the original array.
2. **`Object.keys(o)`**: This option uses the `keys` method (not the standard `Object.keys()`) to get an array of the keys of the object `o`.

**Pros and Cons**

1. **`a.map(i => i.x)`**:
	* Pros: Efficient way to create a new array with transformed data.
	* Cons: Creates a new array, which may incur memory allocation overhead.
2. **`Object.keys(o)`**:
	* Pros: Does not create a new array; returns an array of existing keys.
	* Cons: May be slower due to the need to iterate over the object's properties.

In general, using `map()` can be beneficial when you need to process data in parallel or transform it in some way. However, if memory allocation is a concern, using `Object.keys()` might be a better choice.

**Library and Purpose**

There is no explicit library mentioned in the benchmark definition. The `keys` method appears to be an internal method used by browsers to get an array of object keys.

**Special JS Features or Syntax**

None are explicitly mentioned.

**Other Alternatives**

For creating arrays with transformed data, other options might include:

* Using a `forEach()` loop instead of `map()`: `a.forEach(i => o.push(i.x))`
* Using the spread operator (`...`) to create a new array: `o = [...a.map(i => i.x)]`

However, these alternatives are not used in this benchmark.

**Device Platform and Operating System**

The device platform is listed as "Other", which suggests that the test was run on a browser or emulator. The operating system is listed as "Windows 8.1".

**Additional Considerations**

* The `ExecutionsPerSecond` value indicates how many times each test case was executed per second.
* The benchmark results show that Chrome 54 performed better for both test cases, suggesting that this specific version of the browser might be optimized for these operations.

I hope this explanation helps!

Related benchmarks:

map vs keys (version: 0)

Comparing performance of: map vs keys

Created: 9 years ago by: Guest

Jump to the latest result

map

keys

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):