Benchmark: Create new - MeasureThat.net

Tests:

Map
let prices = { banana: 1, orange: 2, meat: 4, }; let doublePrices = Object.fromEntries( // convert prices to array, map each key/value pair into another pair // and then fromEntries gives back the object Object.entries(prices).map(entry => [entry[0], entry[1] * 2]) );
Entries with array
let prices = { banana: 1, orange: 2, meat: 4, }; let doublePrices = {} for (const [key, value] of Object.entries(prices)) { doublePrices[key] = value }
Entries no array
let prices = { banana: 1, orange: 2, meat: 4, }; let doublePrices = {} Object.entries(prices).forEach((price) => { doublePrices[price[0]] = price[1] })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map
Entries with array
Entries no array

Fastest: N/A

Slowest: N/A

Latest 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 benchmark and explain what is being tested.

**Benchmark Definition**

The benchmark definition is a JSON object that contains information about the benchmark. However, in this case, it only contains three properties:

* "Name": The name of the benchmark, which is "Create new".
* "Description": An empty string, indicating that there is no description for this benchmark.
* "Script Preparation Code" and "Html Preparation Code": Both are empty strings, indicating that no preparation code is needed.

**Test Cases**

There are three test cases:

1. **Map**
The test case uses the `map()` function to create a new object with double values from an existing object. The benchmark definition is:
```javascript
let prices = { banana: 1, orange: 2, meat: 4 };
let doublePrices = Object.fromEntries(
  // convert prices to array, map each key/value pair into another pair
  // and then fromEntries gives back the object
  Object.entries(prices).map(entry => [entry[0], entry[1] * 2])
);
```
The purpose of this test case is to measure the performance of using the `map()` function with an array-like object (in this case, an object with `entries()` method).

2. **Entries with Array**
The test case uses a traditional for loop and the `Object.entries()` method to create a new object with double values from an existing object. The benchmark definition is:
```javascript
let prices = { banana: 1, orange: 2, meat: 4 };
let doublePrices = {};
for (const [key, value] of Object.entries(prices)) {
  doublePrices[key] = value;
}
```
The purpose of this test case is to measure the performance of using a traditional for loop with the `Object.entries()` method.

3. **Entries no Array**
The test case uses the `forEach()` method and the `Object.entries()` method to create a new object with double values from an existing object. The benchmark definition is:
```javascript
let prices = { banana: 1, orange: 2, meat: 4 };
let doublePrices = {};
Object.entries(prices).forEach((price) => {
  doublePrices[price[0]] = price[1];
});
```
The purpose of this test case is to measure the performance of using the `forEach()` method with the `Object.entries()` method.

**Library**

None, as all test cases use built-in JavaScript methods and objects.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntax used in these test cases. However, it's worth noting that some browsers may optimize certain operations differently due to their internal implementations.

**Other Considerations**

* The benchmark uses a small number of iterations to measure performance, which is common in microbenchmarking.
* The benchmark runs on the client-side (in a browser), which can introduce additional overhead compared to running benchmarks on the server-side.
* The test cases use a simple object with three properties, which is likely chosen for its simplicity and minimalism.

**Alternatives**

There are several alternatives for creating new objects in JavaScript, including:

* Using `Object.create()` or `Object.assign()`
* Using a library like Lodash
* Using a different approach, such as using a Map or a Set

However, the test cases above focus on using built-in methods and objects, which is likely chosen to keep the benchmark simple and focused on the performance of those specific operations.

Related benchmarks:

Create new (version: 0)

Comparing performance of: Map vs Entries with array vs Entries no array

Created: 4 years ago by: Guest

Jump to the latest result

Map

Entries with array

Entries no array

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):