Benchmark: Array Summation - MeasureThat.net

Script Preparation code:

window.arr = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99];

Tests:

Reduce
arr.reduce((a, b) => a + b, 0)
Incrementing For Loop
let sum = 0 for(let i = 0; i < arr.length; i++) sum += arr[i]
Decrementing For Loop
let sum =0; for (let i = arr.length; i--;) sum += arr[i]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Reduce
Incrementing For Loop
Decrementing For Loop

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 8 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36

Browser/OS: Chrome 52 on Mac OS X 10.11.6

View result in a separate tab

Test name	Executions per second
Reduce	547437.8 Ops/sec
Incrementing For Loop	23550.0 Ops/sec
Decrementing For Loop	44917.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring the performance of JavaScript code can be a complex task, and BenchmarkThat.net provides a helpful platform for comparing different approaches.

**Overview of the Benchmark**

The benchmark measures the performance of three different ways to calculate the sum of an array: using `reduce()`, `incrementing for loop`, and `decrementing for loop`. The test case uses a predefined array with 50 elements, which is passed to each method.

**Options Compared**

1. **`arr.reduce((a, b) => a + b, 0)`**: This option uses the built-in `reduce()` method of JavaScript arrays. It iterates through the array, adding each element to a running total.
2. **Incrementing For Loop**: This option uses a traditional for loop that increments a counter variable until it reaches the end of the array. At each iteration, it adds the current element to a running sum.
3. **Decrementing For Loop**: This option is similar to the incrementing for loop but decrements the counter variable instead.

**Pros and Cons**

1. **`arr.reduce()`**:
	* Pros: concise and readable code, easy to understand and maintain.
	* Cons: slower than traditional loops due to the overhead of function calls and object lookups.
2. **Incrementing For Loop**:
	* Pros: fast execution speed due to direct access to array elements, simple to implement.
	* Cons: less readable code, may require additional variables for indexing and iteration management.
3. **Decrementing For Loop**:
	* Pros: similar performance to incrementing loop, but with a slight overhead due to the decrement operation.
	* Cons: slightly more complex than incrementing loop due to the decrement operation.

**Library and Special JavaScript Features**

None of these options rely on specific libraries or advanced JavaScript features. However, it's worth noting that some browsers may have optimizations for certain methods or loops, which could affect performance.

**Other Considerations**

When measuring performance in JavaScript, there are several other factors to consider:

1. **Context and Scope**: The execution context and scope can significantly impact performance. For example, the `reduce()` method creates a new array with the accumulated results, while traditional loops modify the original array.
2. **Array Size and Density**: Larger arrays or arrays with more elements may exhibit different performance characteristics due to caching and memory access patterns.
3. **Loop Optimization**: Some browsers optimize loops for certain use cases, such as `while` loops instead of `for` loops.

**Alternatives**

Other alternatives to these three options include:

1. **Using `forEach()` and adding a callback function**: This approach uses the `forEach()` method to iterate through the array and adds a callback function to calculate the sum.
2. **Using `map()` and `reduce()` in combination**: This approach uses the `map()` method to create an array of calculated values and then applies the `reduce()` method to accumulate the results.
3. **Using SIMD instructions (if available)**: If the browser supports SIMD (Single Instruction, Multiple Data) instructions, you can use them to perform operations on multiple elements simultaneously.

Keep in mind that each alternative has its own pros and cons, and the best approach depends on the specific requirements of your project.

Related benchmarks:

Array Summation (version: 0)

Comparing performance of: Reduce vs Incrementing For Loop vs Decrementing For Loop

Created: 8 years ago by: Guest

Jump to the latest result

Reduce

Incrementing For Loop

Decrementing For Loop

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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