Benchmark: reduce vs loop - MeasureThat.net

Script Preparation code:

t = [];
for (let i=0; i < 50; i++) t.push(Math.random());

Tests:

reduce
t.reduce((p,c) => p+c, 0);
loop
(() => { let res = 0; for (let i=0;i<t.length;i++) res += t[i]; return res;})();
loop2
(() => { var i, res; for (i=res=0;i<t.length;i++) res += t[i]; return res;})();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce
loop
loop2

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

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**Overview**

The provided benchmark tests two approaches to calculate the sum of an array: using the `reduce` method and a traditional loop. The test is designed to compare the performance of these two methods.

**Benchmark Definition JSON**

The benchmark definition JSON consists of three main sections:

1. **Name**: A unique identifier for the benchmark.
2. **Script Preparation Code**: This code prepares the data used in the benchmark. In this case, it creates an array `t` with 50 random numbers between 0 and 1.
3. **Html Preparation Code**: This section is empty, indicating that no HTML preparation is required.

**Individual Test Cases**

There are three test cases:

1. **reduce**: Uses the `reduce` method to calculate the sum of the array elements, starting from an initial value of 0. The callback function `(p, c) => p + c` adds each element to the accumulator `p`.
2. **loop**: Uses a traditional loop to iterate over the array and add each element to a running total stored in `res`.
3. **loop2**: Similar to the previous test case, but with a different syntax for declaring variables (`var i, res;` instead of `let i, res;`).

**Library Usage**

In the `reduce` test case, the `reduce` method is used, which is a part of the Array.prototype. The purpose of this library is to provide a concise way to calculate the sum of an array by applying a reduction function to each element.

**Special JavaScript Features or Syntax**

The benchmark uses some advanced syntax features:

* Arrow functions (`(p, c) => p + c` and `(() => {...})`)
* Let and var declarations (in test cases 2 and 3)
* Template literals (not used in this example)

**Performance Comparison**

The performance comparison is based on the number of executions per second. The results indicate that:

* The `reduce` method performs significantly better than the traditional loop, with a ratio of approximately 41:1.
* Test cases 2 and 3 have similar execution rates, but still outperform the `reduce` method.

**Other Alternatives**

If you're interested in exploring alternative approaches to calculate the sum of an array, here are some options:

* Using `forEach` loop: Instead of using a traditional loop, you can use the `forEach` method to iterate over the array and add each element to a running total.
* Using `every` method: The `every` method can be used to check if all elements in an array meet a condition. However, this approach would require some creative thinking to calculate the sum.

Keep in mind that these alternatives might not be as efficient or straightforward as using the `reduce` method or traditional loop.

Related benchmarks:

reduce vs loop (version: 0)

Comparing performance of: reduce vs loop vs loop2

Created: 9 years ago by: Guest

Jump to the latest result

reduce

loop

loop2

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):