Benchmark: Foreach vs. for vs. while on array looping

Tests:

each
var array = [0,1,2,3,4]; array.forEach((num) => { console.log(num); });
for
var array = [0,1,2,3,4]; for (var i = 0; i < array.length; i++) { console.log(array[i]); };
while
var array = [0,1,2,3,4]; var i = 0; while (i < array.length) { console.log(array[i]); i++; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
each
for
while

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 8 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.59 Safari/537.36

Browser/OS: Chrome 54 on Windows

View result in a separate tab

Test name	Executions per second
each	4101.8 Ops/sec
for	4196.0 Ops/sec
while	2933.2 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll explain the benchmark test and its different approaches.

**Overview of the Benchmark**

The benchmark tests three ways to loop through an array in JavaScript: `forEach`, `for`, and `while`. The goal is to determine which approach is fastest.

**Looping Approaches**

There are three main looping approaches being tested:

1. **`forEach()`**: This method calls a provided function once for each element in the array, with the current element as an argument. In this benchmark, it's used to log each element of the `array` variable.
2. **`for` loop**: A traditional loop that uses a counter variable (`i`) to iterate through the array. It checks the length of the array and increments the counter until it reaches the end.
3. **`while` loop**: A loop that continues as long as a certain condition is met (in this case, `i < array.length`). The loop body executes each iteration.

**Pros and Cons**

Here's a brief overview of each approach:

1. **`forEach()`**:
	* Pros: concise, easy to read, and suitable for asynchronous code.
	* Cons: can be slower due to the overhead of function calls and closures.
2. **`for` loop**:
	* Pros: simple, efficient, and well-supported by most engines.
	* Cons: can lead to magic numbers (e.g., `array.length`) and is less intuitive for some developers.
3. **`while` loop**:
	* Pros: flexible, easy to understand, and allows for more control over the iteration process.
	* Cons: may be slower due to the overhead of conditional checks and increment operations.

**Library Usage**

None of the benchmark test cases use a library explicitly. However, it's worth noting that some JavaScript engines, like V8 (used by Chrome), have built-in optimizations and features that can affect performance in certain scenarios.

**Special JS Features or Syntax**

The benchmark does not use any special JavaScript features or syntax, such as `async/await`, `promises`, or modern array methods like `map()` or `filter()`. It only focuses on the basic looping approaches mentioned above.

**Other Alternatives**

If you're interested in exploring alternative ways to loop through arrays in JavaScript, here are a few examples:

1. **`reduce()`**: A method that accumulates values in an array by applying a reduction function to each element.
2. **`every()`, `some()`, and `forEach()` with `Array.prototype.forEach.call()`**: These methods can be used to iterate over arrays using a similar approach to `for` loops.

Overall, the benchmark provides a straightforward way to compare the performance of three common looping approaches in JavaScript, allowing developers to choose the most efficient method for their specific use case.

Related benchmarks:

Foreach vs. for vs. while on array looping (version: 0)

Comparing performance of: each vs for vs while

Created: 8 years ago by: Guest

Jump to the latest result

each

for

while

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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