Benchmark: spread vs mutation vs Object.assign for reduce callback vs for...of loop vs for loop 30K iterations

Tests:

with spread operator

const range = (from, to) => {
  const output = []
  for(var x = from; x < to; x++){
    output.push(x)
  }
  return output
}
range(0, 30000).reduce((acc, num) => {
  return {
    ...acc,
    [num]: num
  }
}, {})

AخA
 
const range = (from, to) => {  const output = []  for(var x = from; x < to; x++){    output.push(x)  }  return output}range(0, 30000).reduce((acc, num) => {  return {    ...acc,    [num]: num  }}, {})

with mutation

const range = (from, to) => {
  const output = []
  for(var x = from; x < to; x++){
    output.push(x)
  }
  return output
}
range(0, 30000).reduce((acc, num) => {
  acc[num] = num
  return acc
}, {})

 
const range = (from, to) => {  const output = []  for(var x = from; x < to; x++){    output.push(x)  }  return output}range(0, 30000).reduce((acc, num) => {  acc[num] = num  return acc}, {})

with object assign

const range = (from, to) => {
  const output = []
  for(var x = from; x < to; x++){
    output.push(x)
  }
  return output
}
range(0, 30000).reduce((acc, num) => {
  return Object.assign(acc, {[num]: num})
}, {})

 
const range = (from, to) => {  const output = []  for(var x = from; x < to; x++){    output.push(x)  }  return output}range(0, 30000).reduce((acc, num) => {  return Object.assign(acc, {[num]: num})}, {})

with for...of loop

const range = (from, to) => {
  const output = []
  for(var x = from; x < to; x++){
    output.push(x)
  }
  return output
}

const items = range(0, 30000);
let result = {};
for(let item of items) {
  result[item] = item;
}

​x
 
const range = (from, to) => {  const output = []  for(var x = from; x < to; x++){    output.push(x)  }  return output}​const items = range(0, 30000);let result = {};for(let item of items) {  result[item] = item;}

with for loop

const range = (from, to) => {
  const output = []
  for(var x = from; x < to; x++){
    output.push(x)
  }
  return output
}

const items = range(0, 30000);
let result = {};
for(let i = 0; i < items.length; i += 1) {
  result[items[i]] = items[i];
}

 
const range = (from, to) => {  const output = []  for(var x = from; x < to; x++){    output.push(x)  }  return output}​const items = range(0, 30000);let result = {};for(let i = 0; i < items.length; i += 1) {  result[items[i]] = items[i];}

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
with spread operator
with mutation
with object assign
with for...of loop
with for loop

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Windows

View result in a separate tab

Test name	Executions per second
with spread operator	0.7 Ops/sec
with mutation	741.3 Ops/sec
with object assign	25.5 Ops/sec
with for...of loop	1132.7 Ops/sec
with for loop	1206.1 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

Let's dive into the explanation of the provided benchmark.

Benchmark Overview

The benchmark measures the performance of four different approaches to populate an object with values from a range:

Using a for loop
Using a for...of loop
Using mutation (directly assigning values to the object)
Using the spread operator (Object.assign)

Approach 1: For Loop

This approach uses a traditional for loop to iterate over the range and assign each value to the object.

Pros:

Easy to understand and implement
Works well for small to medium-sized ranges

Cons:

Can be slow for large ranges due to the overhead of the loop control and array indexing

Approach 2: For...Of Loop

This approach uses a for...of loop, which is more concise and efficient than a traditional for loop. It also allows for easier iteration over arrays.

Pros:

More concise and readable code
Can be faster for large ranges due to the optimized loop control

Cons:

May not work well with older browsers or versions of JavaScript that don't support for...of

Approach 3: Mutation

This approach uses direct assignment to add values to the object.

Pros:

Very concise and easy to understand
Works well for small to medium-sized ranges

Cons:

Can be slow due to the overhead of the assignment operation
May lead to unexpected behavior if not used carefully

Approach 4: Spread Operator

This approach uses the spread operator (Object.assign) to create a new object and assign values from an array.

Pros:

Very concise and easy to understand
Can be faster than mutation for large ranges due to optimized assignment operations

Cons:

May not work well with older browsers or versions of JavaScript that don't support Object.assign
May lead to unexpected behavior if not used carefully (e.g., if the object is modified while being assigned to)

Other Considerations

The use of a spread operator (Object.assign) allows for efficient assignment of values from an array, but it requires careful consideration of the implications of modifying an existing object.
The for...of loop provides a more concise and readable alternative to traditional for loops, but its performance may vary depending on the browser and JavaScript version.

Alternative Approaches

Some other approaches that could be considered for this benchmark include:

Using a library like Lodash or Ramda, which provide optimized functions for working with arrays and objects.
Using a more modern approach like Array.prototype.reduce() or Object.fromEntries(), which can provide better performance and readability than traditional loops.
Considering the use of parallel processing or multi-threading to take advantage of multiple CPU cores.

Overall, this benchmark provides a useful comparison of different approaches to populate an object with values from a range, highlighting the trade-offs between conciseness, readability, and performance.

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Overview**

The benchmark measures the performance of four different approaches to populate an object with values from a range:

1. Using a `for` loop
2. Using a `for...of` loop
3. Using mutation (directly assigning values to the object)
4. Using the spread operator (`Object.assign`)

**Approach 1: For Loop**

This approach uses a traditional `for` loop to iterate over the range and assign each value to the object.

Pros:

* Easy to understand and implement
* Works well for small to medium-sized ranges

Cons:

* Can be slow for large ranges due to the overhead of the loop control and array indexing

**Approach 2: For...Of Loop**

This approach uses a `for...of` loop, which is more concise and efficient than a traditional `for` loop. It also allows for easier iteration over arrays.

Pros:

* More concise and readable code
* Can be faster for large ranges due to the optimized loop control

Cons:

* May not work well with older browsers or versions of JavaScript that don't support `for...of`

**Approach 3: Mutation**

This approach uses direct assignment to add values to the object.

Pros:

* Very concise and easy to understand
* Works well for small to medium-sized ranges

Cons:

* Can be slow due to the overhead of the assignment operation
* May lead to unexpected behavior if not used carefully

**Approach 4: Spread Operator**

This approach uses the spread operator (`Object.assign`) to create a new object and assign values from an array.

Pros:

* Very concise and easy to understand
* Can be faster than mutation for large ranges due to optimized assignment operations

Cons:

* May not work well with older browsers or versions of JavaScript that don't support `Object.assign`
* May lead to unexpected behavior if not used carefully (e.g., if the object is modified while being assigned to)

**Other Considerations**

* The use of a spread operator (`Object.assign`) allows for efficient assignment of values from an array, but it requires careful consideration of the implications of modifying an existing object.
* The `for...of` loop provides a more concise and readable alternative to traditional `for` loops, but its performance may vary depending on the browser and JavaScript version.

**Alternative Approaches**

Some other approaches that could be considered for this benchmark include:

* Using a library like Lodash or Ramda, which provide optimized functions for working with arrays and objects.
* Using a more modern approach like Array.prototype.reduce() or Object.fromEntries(), which can provide better performance and readability than traditional loops.
* Considering the use of parallel processing or multi-threading to take advantage of multiple CPU cores.

Related benchmarks:

spread vs mutation vs Object.assign for reduce callback vs for...of loop vs for loop 30K iterations (version: 0)

Comparing performance of: with spread operator vs with mutation vs with object assign vs with for...of loop vs with for loop

Created: one year ago by: Registered User

Jump to the latest result

with spread operator

with mutation

with object assign

with for...of loop

with for loop

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):