Benchmark: optimized loop - MeasureThat.net

Script Preparation code:


  var array = new Array();
  for (var i = 0; i < 100000; i++) {
    array.push(i);
  }

Tests:

Unoptimized
var dummy = 0; for (var i = 0; i < array.length; i++) { dummy += array[i]; }
Optimized
var dummy = 0; for (var i = 0, al = array.length; i < al; i++) { dummy += array[i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Unoptimized
Optimized

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition:**

The benchmark is designed to measure the performance of a JavaScript loop that iterates over an array and performs some calculations on each element. The script preparation code creates an empty array with 100,000 elements using `var array = new Array();`, and then populates it with integers from 0 to 99,999 using a for loop.

**Options Compared:**

The benchmark compares two options:

1. **Unoptimized Loop**: This version of the loop uses the traditional for loop syntax, where the loop counter variable (`i`) is declared inside the loop and accessed both in the condition and the iteration statement.
2. **Optimized Loop**: This version uses a more efficient approach, declaring `i` outside the loop with `var i = 0;`, and storing the length of the array in a separate variable `al`. The loop then iterates from `i` to `al` using a single loop counter.

**Pros and Cons:**

* **Unoptimized Loop:**
	+ Pros:
		- Easy to understand and write, as it follows traditional for loop syntax.
	+ Cons:
		- Can be slower due to the need to access the array length multiple times in each iteration.
* **Optimized Loop:**
	+ Pros:
		- Can be faster by avoiding repeated accesses to `array.length` and using a single loop counter.
	+ Cons:
		- Requires a bit more knowledge of JavaScript syntax and might be harder to understand for beginners.

**Library Usage:**

There is no explicit library used in the benchmark. However, the use of `Array.prototype.push()` is implied by the array creation code.

**Special JS Features or Syntax:**

None explicitly mentioned.

**Alternative Approaches:**

Some alternative approaches to optimize loops in JavaScript include:

* Using `for...of` loops instead of traditional for loops.
* Utilizing built-in methods like `forEach()`, `map()`, or `reduce()` for array iteration.
* Leveraging Web Workers or Web Assembly (WASM) for parallel execution.

Keep in mind that the choice of optimization technique depends on the specific use case, performance requirements, and the complexity of the code.

**Benchmark Preparation Code:**

The script preparation code creates an empty array with 100,000 elements using `var array = new Array();` and populates it with integers from 0 to 99,999 using a for loop. The prepared array is used as input in both test cases.

**Individual Test Cases:**

Each test case includes a benchmark definition, which defines the JavaScript code that will be executed. In this case:

* **Unoptimized Loop:** This version uses traditional for loop syntax.
* **Optimized Loop:** This version uses an optimized approach with `i` declared outside the loop and `al` storing the array length.

The test results are stored in a separate data structure, indicating which test case (Unoptimized or Optimized) produced faster execution times.

Related benchmarks:

optimized loop (version: 0)

Comparing performance of: Unoptimized vs Optimized

Created: 7 years ago by: Registered User

Jump to the latest result

Unoptimized

Optimized

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):