Benchmark: for vs foreach vs some vs for..of 1000 (improved)

Script Preparation code:

var array = [];
for (var i = 0; i < 1000; i++) {
    array.push(Math.random() * 1000);
}

Tests:

for
var sum = 0; for (var i = 0; i < array.length; i++) { sum += array[i]; }
foreach
var sum = 0; array.forEach(function(i) { sum += i; });
some
var sum = 0; array.some(function(i) { sum += i; });
for..of
var sum = 0; for (var i of array) { sum += i; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
foreach
some
for..of

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 what's being tested in the provided JSON benchmark.

**Benchmark Overview**

The benchmark is designed to compare the performance of different loop iteration methods:

1. `for` loop
2. `forEach` method (also known as " callback" or "iterable" loops)
3. `some` method (which returns a boolean value indicating whether an element passes a test)
4. `for...of` loop (introduced in ECMAScript 2015, also known as "enhanced for loop")

**Loop Iteration Methods**

Each of these methods has its own pros and cons:

1. **`for` Loop**
	* Pros: Widely supported, easy to understand, allows for direct indexing (`array[i]`)
	* Cons: Can be verbose, doesn't support `Array.prototype.forEach()` or other modern iteration methods
2. **`forEach` Method**
	* Pros: Modern and concise way of iterating over arrays, supports callback functions, and is part of the ECMAScript standard
	* Cons: Requires an additional function to execute for each element, can be slower than `for` loops for large datasets
3. **`some` Method**
	* Pros: Efficiently returns a boolean value indicating whether any element passes a test, useful in situations where you don't need the iteration result
	* Cons: Returns a boolean value instead of an array, requires careful handling of the return value
4. **`for...of` Loop**
	* Pros: Concise and modern way to iterate over arrays, directly access each element (`array[i]`)
	* Cons: Only available in ECMAScript 2015 and later versions, can be slower than `for` loops for very large datasets

**Library Usage**

None of the benchmark cases explicitly use a library. However, some libraries like Lodash or underscore.js provide optimized implementations of these methods.

**Special JavaScript Features/Syntax**

The benchmark doesn't mention any special JavaScript features or syntax that might affect its results. The focus is solely on the loop iteration methods themselves.

**Alternative Loops**

Other alternatives to these loop types include:

* `while` loops: A traditional, non-iterative approach.
* Array.prototype.reduce(): A method for accumulating values in an array using a callback function.
* Array.prototype.map() and Array.prototype.filter(): Methods that return new arrays based on a predicate function.

Keep in mind that the performance differences between these loop types can vary depending on specific use cases, dataset sizes, and browser implementations.

Related benchmarks:

for vs foreach vs some vs for..of 1000 (improved) (version: 0)

Compare loop performance

Comparing performance of: for vs foreach vs some vs for..of

Created: 5 years ago by: Guest

Jump to the latest result

for

foreach

some

for..of

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):