Benchmark: loops: for vs foreach vs some vs for..of

Script Preparation code:

var array = new Array(1000);

Tests:

for
for (var i = 0; i < array.length; i++) { array[i]; }
foreach
array.forEach(function(i) { array[i]; });
some
array.some(function(i) { array[i]; });
for..of
for (var i of array) { array[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 the test cases and explain what is being tested, along with the pros and cons of each approach.

**Test Case: Loops - For vs Foreach vs Some vs For..of**

The goal of this benchmark is to compare the performance of different loop constructs in JavaScript:

1. **For Loop**: This is a traditional loop construct that uses an index variable to iterate over an array.
2. **Foreach Loop**: This loop construct iterates over an array using a callback function, which provides access to both the value and the index of each element.
3. **Some Loop**: This loop construct returns true as soon as the condition is met, making it similar to `break` statement in other languages.
4. **For..of Loop**: This is a more modern loop construct that uses an iterator protocol to iterate over arrays.

**Pros and Cons:**

* **For Loop**:
	+ Pros: Simple, widely supported, and easy to understand.
	+ Cons: Can be slow due to the overhead of indexing into the array.
* **Foreach Loop**:
	+ Pros: Efficient use of memory, as it only stores one value at a time (the callback function).
	+ Cons: Less readable than other loop constructs, as it uses an indirect approach.
* **Some Loop**:
	+ Pros: Can be faster due to early return behavior, but also more error-prone.
	+ Cons: Less intuitive than `break` statement in other languages.
* **For..of Loop**:
	+ Pros: Modern, efficient, and easy to read.
	+ Cons: May not be supported by older browsers or environments.

**Library Usage**

The benchmark uses the built-in JavaScript array functions without any external libraries. However, it's worth noting that if you were to use a library like Lodash, which provides more functional programming constructs, you might see different performance results.

**Special JS Features/Syntax**

This benchmark does not explicitly test any special features or syntax in JavaScript, but the for..of loop is a relatively new feature introduced in ECMAScript 2015 (ES6). The for..of loop is designed to iterate over arrays and other iterable objects using an iterator protocol. It's similar to a traditional `for` loop but provides more convenience and safety features.

**Alternative Benchmarks**

If you wanted to benchmark different aspects of loops, here are some alternative approaches:

* **Array indexing vs Array iteration**: Benchmark the performance of direct array indexing (e.g., `array[i]`) versus using an iterator or a for loop.
* **Loop iteration vs Loop filtering**: Benchmark the performance of simple loop iterations versus more complex loop iterations with conditional statements.
* **Native vs Managed Memory Allocation**: Benchmark the performance of native memory allocation (e.g., using `Buffer` or `Uint8Array`) versus managed memory allocation (e.g., using `new Int32Array()`).
* **Array parallelization vs Sequential execution**: Benchmark the performance of parallelizing loop iterations across multiple CPU cores versus executing loops sequentially.

Related benchmarks:

loops: for vs foreach vs some vs for..of (version: 0)

Compare loop performance

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

Created: 4 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):