Benchmark: Array loop vs foreach vs map vs filter for update field in object

Script Preparation code:

   var arr = [];
   for (var i = 0; i < 1000; i++) {
       arr[i] = {
           'id': i
       };
   }

   function someFn(i) {
       return i * 3 * 8;
   }

​x
 
   var arr = [];   for (var i = 0; i < 1000; i++) {       arr[i] = {           'id': i       };   }​   function someFn(i) {       return i * 3 * 8;   }

Tests:

foreach
arr.forEach(function (item){ item.data = someFn(item.id); })
arr.forEach(function (item){
item.data = someFn(item.id);
})

for

for (var i = 0, len = arr.length; i < len; i++) {
  arr[i].data = someFn(arr[i].id);
}

 
for (var i = 0, len = arr.length; i < len; i++) {  arr[i].data = someFn(arr[i].id);}

map
arr.map(function(item){ item.data=someFn(item.id); });
arr.map(function(item){ item.data=someFn(item.id); });
filter
arr.filter(function(item){ item.data=someFn(item.id); });
arr.filter(function(item){ item.data=someFn(item.id); });

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
foreach
for
map
filter

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.142 Safari/537.36

Browser/OS: Chrome 81 on Windows

View result in a separate tab

Test name	Executions per second
foreach	5817.9 Ops/sec
for	2177.7 Ops/sec
map	5872.2 Ops/sec
filter	5705.6 Ops/sec

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

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided benchmark definition json represents a simple script that creates an array of objects with an id field and then applies a calculation to this data using four different approaches: forEach, for, map, and filter. The purpose of this benchmark is to compare the performance of these four methods in updating the data property of each object.

Options being compared:

forEach: This method iterates over an array, executing a provided function for each element.
for loop: A traditional loop that uses a variable to keep track of the iteration index.
map: This method creates a new array with the results of applying a provided function to each element in the original array.
filter: Similar to map, but it only includes elements for which the provided function returns true.

Pros and cons of each approach:

forEach:
- Pros: Easy to read, concise code, and can be used when iterating over an array.
- Cons: Can be slower than other methods due to the overhead of a separate loop or iterator.
for loop:
- Pros: Often faster than other methods since it uses a traditional loop.
- Cons: More verbose and requires manual indexing, which can increase errors.
map:
- Pros: Can be more efficient for large arrays since it avoids the overhead of multiple iterations (e.g., filtering).
- Cons: Creates a new array, which may not be desirable when memory is limited. Also, can be slower if the function being mapped is expensive.
filter:
- Pros: Similar to map, but only includes elements that pass the test.
- Cons: Can still be slow due to creating a new array and the overhead of filtering.

Library usage:

None of these methods use any external libraries. They are all built-in features of JavaScript.

Special JS feature or syntax:

The provided benchmark definition uses no special features or syntax beyond what's standard in JavaScript.

Now, let's look at some alternatives:

Using a library: There are libraries like Lodash that provide optimized versions of these methods for performance. However, MeasureThat.net is specifically interested in the built-in methods.
Other approaches: Other options could include using reduce, which combines multiple array operations into one; using Promise.all with map and then to handle updates sequentially; or even using a more functional programming approach like recursion.

Keep in mind that performance differences between these methods can vary depending on the specific use case, data size, and JavaScript environment.

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided benchmark definition json represents a simple script that creates an array of objects with an `id` field and then applies a calculation to this data using four different approaches: `forEach`, `for`, `map`, and `filter`. The purpose of this benchmark is to compare the performance of these four methods in updating the `data` property of each object.

**Options being compared:**

1. **`forEach`**: This method iterates over an array, executing a provided function for each element.
2. **`for` loop**: A traditional loop that uses a variable to keep track of the iteration index.
3. **`map`**: This method creates a new array with the results of applying a provided function to each element in the original array.
4. **`filter`**: Similar to `map`, but it only includes elements for which the provided function returns true.

**Pros and cons of each approach:**

*   **`forEach`**:
    *   Pros: Easy to read, concise code, and can be used when iterating over an array.
    *   Cons: Can be slower than other methods due to the overhead of a separate loop or iterator.
*   **`for` loop**:
    *   Pros: Often faster than other methods since it uses a traditional loop.
    *   Cons: More verbose and requires manual indexing, which can increase errors.
*   **`map`**:
    *   Pros: Can be more efficient for large arrays since it avoids the overhead of multiple iterations (e.g., filtering).
    *   Cons: Creates a new array, which may not be desirable when memory is limited. Also, can be slower if the function being mapped is expensive.
*   **`filter`**:
    *   Pros: Similar to `map`, but only includes elements that pass the test.
    *   Cons: Can still be slow due to creating a new array and the overhead of filtering.

**Library usage:**

None of these methods use any external libraries. They are all built-in features of JavaScript.

**Special JS feature or syntax:**

The provided benchmark definition uses no special features or syntax beyond what's standard in JavaScript.

Now, let's look at some alternatives:

*   **Using a library**: There are libraries like Lodash that provide optimized versions of these methods for performance. However, MeasureThat.net is specifically interested in the built-in methods.
*   **Other approaches**: Other options could include using `reduce`, which combines multiple array operations into one; using `Promise.all` with `map` and `then` to handle updates sequentially; or even using a more functional programming approach like recursion.

Keep in mind that performance differences between these methods can vary depending on the specific use case, data size, and JavaScript environment.

Related benchmarks:

Array loop vs foreach vs map vs filter for update field in object (version: 0)

Comparing performance of: foreach vs for vs map vs filter

Created: 5 years ago by: Guest

Jump to the latest result

foreach

for

map

filter

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):