Benchmark: Extract prop from object array

Script Preparation code:

var testArray = []
for(var i=0;i<100000;i++){
  testArray.push({ id: i, val: Math.random()});
}

Tests:

Using Array.prototype.map()
var vals = testArray.map((a) => {return a.val});
Using traditional for loop
var vals=[]; for(var i=0;i<testArray.length;i++){ vals.push(testArray[i].val); }
Using ES6 for..of
var vals=[]; for(var item of testArray){ vals.push(item.val); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using Array.prototype.map()
Using traditional for loop
Using ES6 for..of

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated 29 days ago):

LLMs can make mistakes. Check important info.

This benchmark tests the efficiency of three different ways to extract the `val` property from an array of objects in JavaScript:

**1. Using `Array.prototype.map()`:**

-  This method leverages the built-in `.map()` function which iterates over each element in the array and applies a provided function to it, returning a new array with the results.
   - **Pros:** Concise, readable, and generally considered the most efficient approach for tasks like this. It's optimized for JavaScript engines.
   - **Cons:**  None significant in this context.

**2. Using a traditional `for` loop:**

- This method uses a classic `for` loop to iterate over the indices of the array and access each element individually.
   - **Pros:** More familiar to developers who learned programming before JavaScript's higher-order functions.
   - **Cons:** Less concise than `.map()`, can be harder to read, and generally slower due to manual iteration.

**3. Using ES6 `for...of` loop:**

- This method utilizes the more modern `for...of` loop, which iterates directly over the values of the array rather than its indices. 
   - **Pros:** More concise and readable than the traditional `for` loop, can be slightly faster in some cases.
   - **Cons:**  Requires understanding of ES6 syntax, might not always be significantly faster than `.map()`.

**Other Alternatives:**

- **`reduce()`:** While not as directly applicable here, JavaScript's `reduce()` function could be used to accumulate all the `val` properties into a single array. This would be less efficient for extracting individual values but useful for other tasks.
 - **Libraries:** There aren't any specific libraries used in this benchmark. However, in real-world applications, you might use libraries like Lodash or Ramda which offer optimized versions of common array operations.

Let me know if you have any more questions!

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Firefox/60.0

Browser/OS: Firefox 60 on Mac OS X 10.13

View result in a separate tab

Test name	Executions per second
Using Array.prototype.map()	532.8 Ops/sec
Using traditional for loop	441.9 Ops/sec
Using ES6 for..of	501.1 Ops/sec

Related benchmarks:

Extract prop from object array (version: 0)

Comparing performance of: Using Array.prototype.map() vs Using traditional for loop vs Using ES6 for..of

Created: 6 years ago by: Guest

Jump to the latest result

Using Array.prototype.map()

Using traditional for loop

Using ES6 for..of

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated 29 days ago):