Benchmark: Add property to objects

Tests:

for loop
let a = [{ a: 1, b: 'bar' }, { a: 2, b: 'foo' }, { a: 3, b: 'baz' }] for(let i=0, l=a.length; i<l; i++) { a[i].c = 'zzz' }
map
let a = [{ a: 1, b: 'bar' }, { a: 2, b: 'foo' }, { a: 3, b: 'baz' }] a.map(v => { return { ...v, c: 'zzz' } })
forEach
let a = [{ a: 1, b: 'bar' }, { a: 2, b: 'foo' }, { a: 3, b: 'baz' }] a.forEach(v => { v.c = 'zzz' })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for loop
map
forEach

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Definition**

The benchmark definition is a JSON object that contains metadata about the benchmark. In this case, it provides the following information:

* `Name`: The name of the benchmark, which is "Add property to objects".
* `Description`: A brief description of the benchmark, which is "Add a property to objects in an array".
* `Script Preparation Code` and `Html Preparation Code`: These fields are currently empty, indicating that no custom script or HTML preparation code is required for this benchmark.

**Individual Test Cases**

There are three test cases defined in the benchmark:

1. **"for loop"`**

This test case consists of a single benchmark definition, which includes a JavaScript code snippet that uses a `for` loop to add a new property `c` to each object in an array.

```javascript
for (let i = 0, l = a.length; i < l; i++) {
  a[i].c = 'zzz';
}
```

This test case likely measures the performance of using a traditional `for` loop to iterate over an array and add properties to its elements.

2. **"map"`**

The second test case is similar to the first, but it uses the `Array.prototype.map()` method instead of a traditional `for` loop.

```javascript
a.map(v => {
  return { ...v,
          c: 'zzz'
         };
})
```

This test case likely measures the performance of using the `map()` method to iterate over an array and add properties to its elements.

3. **"forEach"`**

The third test case is also similar to the first, but it uses the `Array.prototype.forEach()` method instead of a traditional `for` loop.

```javascript
a.forEach(v => {
  v.c = 'zzz';
})
```

This test case likely measures the performance of using the `forEach()` method to iterate over an array and add properties to its elements.

**Options Compared**

The three test cases compare different approaches to adding a property to objects in an array:

* **"for loop"`**: Uses a traditional `for` loop to iterate over the array.
* **"map"`**: Uses the `Array.prototype.map()` method to create a new array with the added properties.
* **"forEach"`**: Uses the `Array.prototype.forEach()` method to iterate over the array.

**Pros and Cons**

Here are some pros and cons of each approach:

* **"for loop"`**: Pros:
	+ More control over iteration.
	+ May be more efficient for small arrays.
Cons:
	+ Can be slower for large arrays due to the overhead of the loop.
	+ Less concise than other approaches.
* **"map"`: Pros:
	+ Concise and expressive syntax.
	+ Can create a new array with the added properties.
Cons:
	+ May require more memory allocation.
	+ Less control over iteration.
* **"forEach"`: Pros:
	+ More concise than traditional `for` loops.
	+ Still allows for some level of control over iteration.
Cons:
	+ Less efficient than other approaches for large arrays.

**Libraries and Special JS Features**

There are no libraries used in these test cases. However, the use of `Array.prototype.map()` and `Array.prototype.forEach()` implies that the benchmark is testing modern JavaScript features.

**Other Alternatives**

If you want to add properties to objects in an array, other alternatives could include:

* Using a `for...of` loop instead of a traditional `for` loop.
* Using a library like Lodash or Underscore.js to add properties to arrays.
* Using a functional programming approach with methods like `reduce()` or `filter()`.
* Using a parallel processing library like Web Workers to speed up the testing process.

Keep in mind that these alternatives may have different performance characteristics and may not be suitable for all use cases.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:92.0) Gecko/20100101 Firefox/92.0

Browser/OS: Firefox 92 on Linux

View result in a separate tab

Test name	Executions per second
for loop	7693968.5 Ops/sec
map	2272357.5 Ops/sec
forEach	7262230.5 Ops/sec

Related benchmarks:

Add property to objects (version: 0)

Add a property to objects in an array

Comparing performance of: for loop vs map vs forEach

Created: 3 years ago by: Guest

Jump to the latest result

for loop

map

forEach

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):