Benchmark: forEach vs for vs while

Tests:

forEach
const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; arr.forEach(el => console.log(el));
for
const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; for (let i = 0, len = arr.length; i < len; i++) { console.log(arr[i]); }
while
const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; let i = 0; while (i < arr.length) { console.log(arr[i]); i++; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
forEach
for
while

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/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Windows

View result in a separate tab

Test name	Executions per second
forEach	184.8 Ops/sec
for	199.8 Ops/sec
while	201.7 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark defines three types of loops: `forEach`, `for`, and `while`. The goal is to compare the performance of these three approaches in iterating over an array.

**Options Compared**

We have three options being compared:

1. **`forEach`**: This method iterates over an array using a callback function that is called for each element in the array.
2. **`for`**: This loop uses a traditional `for` loop with an index variable to iterate over the array.
3. **`while`**: This loop uses a conditional statement to check if the loop should continue iterating, based on the value of an index variable.

**Pros and Cons**

Here are some pros and cons of each approach:

* **`forEach`**:
	+ Pros: concise and expressive code, easy to read and maintain.
	+ Cons: can be slower due to the overhead of callback functions.
* **`for`**:
	+ Pros: fast and efficient, predictable loop behavior.
	+ Cons: can be verbose and less readable than `forEach`.
* **`while`**:
	+ Pros: flexible and adjustable loop behavior, but requires more manual management.
	+ Cons: can be error-prone if not managed correctly.

**Library**

In the benchmark code, there is no explicit library being used. However, the `forEach`, `for`, and `while` loops are standard JavaScript constructs that do not rely on external libraries.

**Special JS Features or Syntax**

There are no special JavaScript features or syntax being tested in this benchmark. The focus is solely on comparing the performance of different loop approaches.

**Other Considerations**

When choosing a loop approach, consider the following factors:

* Code readability and maintainability
* Performance requirements (e.g., speed, efficiency)
* Development time and ease of use

In general, if you need to iterate over an array frequently, `forEach` is a good choice due to its concise and expressive nature. However, if performance is critical, a traditional `for` loop or `while` loop may be more suitable.

**Alternatives**

If you're looking for alternative loop approaches, consider the following options:

* **`reduce()`**: A method that accumulates values in an array by applying a callback function to each element.
* **`map()`**: A method that creates a new array with transformed values using a callback function.
* **`every()`, `some()`, and `any()`**: Methods that test conditions on elements of an array.

Keep in mind that these methods may have different performance characteristics than the traditional loop approaches.

Related benchmarks:

forEach vs for vs while (version: 0)

Test array forEach, for, while

Comparing performance of: forEach vs for vs while

Created: 6 years ago by: Guest

Jump to the latest result

forEach

for

while

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):