Benchmark: Array loop vs foreach vs while

Script Preparation code:

   var arr = [];
    for (var i = 0; i < 1000000; i++) {
      arr[i] = i;
    }

Tests:

foreach
arr.forEach(function (item){ })
for
for (var i = 0, len = arr.length; i < len; i++) { }
while
let i = 0, len = arr.length; while (i<len) { 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:

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

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Let's break down the provided benchmark and its test cases.

**Benchmark Overview**

The benchmark, called "Array loop vs foreach vs while," compares the performance of three different ways to iterate over an array: `forEach`, `for`, and `while`. The test case is designed to measure which approach is fastest for a large array of 1 million elements.

**Script Preparation Code**

The script preparation code creates an empty array `arr` with 1 million elements, where each element is initialized to its index value (`i`) in the loop.

**Html Preparation Code**

There is no HTML preparation code provided, which suggests that the benchmark is focused solely on JavaScript performance and does not involve any additional computations or external dependencies.

**Test Cases**

The test cases are represented as an array of objects, each containing a `Benchmark Definition` string, a `Test Name`, and other metadata. There are three test cases:

1. **foreach**: This test case uses the `forEach` method to iterate over the array.
2. **for**: This test case uses a traditional `for` loop to iterate over the array.
3. **while**: This test case uses a `while` loop to iterate over the array.

**Library Used:**

There is no explicit library mentioned in the benchmark definition or test cases. However, the use of modern JavaScript features like arrow functions (`=>`) and template literals (`\r\n  \n`) suggests that the test code is using ECMAScript 2015 (ES6) syntax.

**Special JS Features/Syntax:**

None are explicitly mentioned, but the use of ES6 syntax and the `forEach` method implies that the test code is using modern JavaScript features.

**Options Compared:**

The three options being compared are:

1. **Array.prototype.forEach()**: A built-in method for iterating over arrays.
2. **Traditional `for` loop**: A common way to iterate over arrays using a loop variable and an increment operator.
3. **While loop**: A control structure that can be used to iterate over arrays by looping until a condition is met.

**Pros and Cons of Each Approach:**

1. **Array.prototype.forEach()**:
	* Pros: concise, readable, and easy to use. It's also a built-in method, so it's familiar to many developers.
	* Cons: can be slower than traditional loops due to the overhead of creating an iterator object.
2. **Traditional `for` loop**:
	* Pros: can be faster than `forEach` because it avoids creating an iterator object.
	* Cons: can be verbose and less readable, especially for complex iterations.
3. **While loop**:
	* Pros: flexible, easy to use, and can be faster than traditional loops due to the lack of overhead from creating an iterator object.
	* Cons: requires more code and can be less readable than `forEach` or traditional `for` loops.

**Other Alternatives:**

Some alternative approaches that could have been used in this benchmark include:

1. **Array.prototype.reduce()**: While not a true iteration method, it's another common way to process arrays iteratively.
2. **Set**: For iterating over unique values in an array.
3. **Promise.all()**: For executing multiple iterations concurrently.

These alternatives might be worth exploring in a different benchmark or test scenario.

Related benchmarks:

Array loop vs foreach vs while (version: 0)

Comparing performance of: foreach vs for vs while

Created: 4 years ago by: Guest

Jump to the latest result

foreach

for

while

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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