Benchmark: Reduce and Spread vs. Foreach and Mutate 3

Script Preparation code:

var objectsArray = Array(1000).fill(() => {
  const key = Math.random().toString(36).substring(2, 5);
  const value = Math.random().toString(36).substring(2, 5);
  return {[key]: value};
});

AخA
 
var objectsArray = Array(1000).fill(() => {  const key = Math.random().toString(36).substring(2, 5);  const value = Math.random().toString(36).substring(2, 5);  return {[key]: value};});

Tests:

Reduce and Spread
var combined = objectsArray.reduce((memo, obj) => ({...memo, ...obj}), {});
var combined = objectsArray.reduce((memo, obj) => ({...memo, ...obj}), {});
ForEach and Mutate (for .. in loop)
var combined = {} objectsArray.forEach(obj => { for (key in obj) { combined[key] = obj[key]; } });
var combined = {}
objectsArray.forEach(obj => {
for (key in obj) {
combined[key] = obj[key];
}
});
Mutate with Object.assign
var combined = Object.assign(...objectsArray)
var combined = Object.assign(...objectsArray)
Foreach and Mutate (Object.assign)
var combined = {} objectsArray.forEach(obj => Object.assign(combined, obj));
var combined = {}
objectsArray.forEach(obj => Object.assign(combined, obj));
Reduce Mutate
var combined = objectsArray.reduce((memo, obj) => Object.assign(memo, obj), {});
var combined = objectsArray.reduce((memo, obj) => Object.assign(memo, obj), {});

reduce mutate 2

var combined = objectsArray.reduce((acc, obj) => {
  for (key in obj) {
    acc[key] = obj[key];
  }
  return acc;
}, {});

 
var combined = objectsArray.reduce((acc, obj) => {  for (key in obj) {    acc[key] = obj[key];  }  return acc;}, {});

reduce mutate 3
var combined = objectsArray.reduce((acc, obj) => { Object.keys(obj).forEach((key) => acc[key] = obj[key]); return acc; }, {});
var combined = objectsArray.reduce((acc, obj) => {
Object.keys(obj).forEach((key) => acc[key] = obj[key]);
return acc;
}, {});

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Experimental features:

Memory measurements supported only in Chrome.
For precise memory measurements Chrome must be launched with --enable-precise-memory-info flag.
More information: Monitoring JavaScript Memory

Test case name	Result
Reduce and Spread
ForEach and Mutate (for .. in loop)
Mutate with Object.assign
Foreach and Mutate (Object.assign)
Reduce Mutate
reduce mutate 2
reduce mutate 3

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 7 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36

Browser/OS: Chrome 127 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Reduce and Spread	56009.0 Ops/sec
ForEach and Mutate (for .. in loop)	237257.6 Ops/sec
Mutate with Object.assign	159431.8 Ops/sec
Foreach and Mutate (Object.assign)	13880.9 Ops/sec
Reduce Mutate	15005.5 Ops/sec
reduce mutate 2	232357.6 Ops/sec
reduce mutate 3	14103.1 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 4 months ago):

Let's dive into the world of JavaScript microbenchmarks.

What is tested?

The provided JSON represents a set of benchmark tests that compare different approaches to merge and manipulate arrays in JavaScript. The tests measure the performance of various methods, including:

reduce with spreading (Reduce and Spread)
forEach with mutating loops (ForEach and Mutate (for .. in loop))
Object.assign
Combining reduce with Object.assign or using forEach with Object.assign

Options compared

The tests compare the following options:

Reduce with spreading: Using the spread operator (...) to merge objects into a new object.
ForEach with mutating loops: Using a traditional for loop to iterate over each object in the array and update a target object.
Object.assign: Using the Object.assign method to merge one or more targets into a single object.
Combining reduce with Object.assign: Using reduce to iterate over the array and merge objects using Object.assign.
ForEach with Object.assign: Using forEach to iterate over each object in the array and update a target object using Object.assign.

Pros and cons of each approach

Here's a brief summary of the pros and cons of each approach:

Reduce with spreading:
- Pros: concise, efficient, and easy to read.
- Cons: may not work as expected if objects have complex structures or circular references.
ForEach with mutating loops:
- Pros: can handle complex object structures and circular references.
- Cons: verbose, error-prone, and may have performance issues due to the use of explicit loops.
Object.assign:
- Pros: efficient, flexible, and widely supported.
- Cons: may not work as expected if objects are not plain objects or if there are circular references.
Combining reduce with Object.assign:
- Pros: handles complex object structures and circular references efficiently.
- Cons: may be less readable than other approaches.
ForEach with Object.assign:
- Pros: concise, easy to read, and efficient.
- Cons: may not handle complex object structures or circular references as well as other approaches.

Other considerations

When choosing an approach, consider the following factors:

Readability: How easy is it to understand and maintain your code?
Performance: How efficient is your code in terms of execution time and memory usage?
Complexity: Can your code handle complex object structures or circular references?
Browser support: Are you targeting specific browsers that may have quirks or differences in how they handle these approaches?

Other alternatives

If none of the above approaches suit your needs, consider alternative methods:

Lodash's merge function: A comprehensive utility library for functional programming.
Underscore.js's _.extend function: Another popular utility library for functional programming.

These libraries provide a range of useful functions for merging and manipulating objects in JavaScript, including those that handle complex object structures and circular references.

I hope this helps you navigate the world of JavaScript microbenchmarks!

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**What is tested?**

The provided JSON represents a set of benchmark tests that compare different approaches to merge and manipulate arrays in JavaScript. The tests measure the performance of various methods, including:

1. `reduce` with spreading (`Reduce and Spread`)
2. `forEach` with mutating loops (`ForEach and Mutate (for .. in loop)`)
3. `Object.assign`
4. Combining `reduce` with `Object.assign` or using `forEach` with `Object.assign`

**Options compared**

The tests compare the following options:

1. **Reduce with spreading**: Using the spread operator (`...`) to merge objects into a new object.
2. **ForEach with mutating loops**: Using a traditional `for` loop to iterate over each object in the array and update a target object.
3. **Object.assign**: Using the `Object.assign` method to merge one or more targets into a single object.
4. **Combining reduce with Object.assign**: Using `reduce` to iterate over the array and merge objects using `Object.assign`.
5. **ForEach with Object.assign**: Using `forEach` to iterate over each object in the array and update a target object using `Object.assign`.

**Pros and cons of each approach**

Here's a brief summary of the pros and cons of each approach:

1. **Reduce with spreading**:
	* Pros: concise, efficient, and easy to read.
	* Cons: may not work as expected if objects have complex structures or circular references.
2. **ForEach with mutating loops**:
	* Pros: can handle complex object structures and circular references.
	* Cons: verbose, error-prone, and may have performance issues due to the use of explicit loops.
3. **Object.assign**:
	* Pros: efficient, flexible, and widely supported.
	* Cons: may not work as expected if objects are not plain objects or if there are circular references.
4. **Combining reduce with Object.assign**:
	* Pros: handles complex object structures and circular references efficiently.
	* Cons: may be less readable than other approaches.
5. **ForEach with Object.assign**:
	* Pros: concise, easy to read, and efficient.
	* Cons: may not handle complex object structures or circular references as well as other approaches.

**Other considerations**

When choosing an approach, consider the following factors:

1. **Readability**: How easy is it to understand and maintain your code?
2. **Performance**: How efficient is your code in terms of execution time and memory usage?
3. **Complexity**: Can your code handle complex object structures or circular references?
4. **Browser support**: Are you targeting specific browsers that may have quirks or differences in how they handle these approaches?

**Other alternatives**

If none of the above approaches suit your needs, consider alternative methods:

1. **Lodash's `merge` function**: A comprehensive utility library for functional programming.
2. **Underscore.js's `_.extend` function**: Another popular utility library for functional programming.

These libraries provide a range of useful functions for merging and manipulating objects in JavaScript, including those that handle complex object structures and circular references.

I hope this helps you navigate the world of JavaScript microbenchmarks!

Related benchmarks:

Reduce and Spread vs. Foreach and Mutate 3 (version: 0)

Comparing performance of: Reduce and Spread vs ForEach and Mutate (for .. in loop) vs Mutate with Object.assign vs Foreach and Mutate (Object.assign) vs Reduce Mutate vs reduce mutate 2 vs reduce mutate 3

Created: 4 years ago by: Registered User

Jump to the latest result

Reduce and Spread

ForEach and Mutate (for .. in loop)

Mutate with Object.assign

Foreach and Mutate (Object.assign)

Reduce Mutate