Benchmark: Loops of loops VS. Manual Loops

Script Preparation code:

var size = 1000000;
var arr = [];

for (var i=0; i < size; i++) {
  arr.push(i);
}

Tests:

All finds in one loop
var index1 = -1; var index2 = -1; var index3 = -1; var index4 = -1; var index5 = -1; for (var ii=0; ii < arr.length; ii++) { if (i === 23423) { index1 = i; } else if (i === 3453) { index2 = i; } else if (i === 9877) { index3 = i; } else if (i === 39248) { index4 = i; } else if (i === 908098) { index5 = i; } }
Manual finds with multiple loops
function findIndex(list, thing) { var foundIndex = -1; for (var i=0; i < list.length; i++) { if (i === thing) { foundIndex = i; } } return foundIndex; } var index1 = findIndex(arr, 23423); var index2 = findIndex(arr, 3453); var index3 = findIndex(arr, 9877); var index4 = findIndex(arr, 39248); var index5 = findIndex(arr, 908098);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
All finds in one loop
Manual finds with multiple loops

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0

Browser/OS: Firefox 60 on Ubuntu

View result in a separate tab

Test name	Executions per second
All finds in one loop	63.8 Ops/sec
Manual finds with multiple loops	358.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested.

**Benchmark Definition:**
The benchmark compares two approaches to find specific indices in an array:

1. **Manual Loops:** This approach uses multiple loops to iterate through the array, checking for the desired index in each iteration.
2. **FindIndex Library Function:** This approach uses a built-in JavaScript function called `findIndex()` that takes two arguments: the array and the value to search for. It returns the index of the first occurrence of the value, or -1 if not found.

**What is tested on the provided JSON?**

The benchmark tests the performance difference between these two approaches in finding specific indices in an array with 6 million elements. The test cases are:

* **All finds in one loop:** This test case uses a single loop to find all six indices using manual loops.
* **Manual finds with multiple loops:** This test case also uses manual loops, but splits the search into five separate iterations.

**Options Compared:**

The benchmark compares the performance of two approaches:

1. **Manual Loops:** This approach requires explicit looping through the array and conditional checks to find the desired index.
2. **FindIndex Library Function:** This approach uses a built-in function that abstracts away the iteration and condition checking, making it more concise but potentially slower due to additional overhead.

**Pros and Cons:**

* **Manual Loops:**
	+ Pros:
		- Control over the iteration and conditional checks.
		- No reliance on external libraries or functions.
	+ Cons:
		- Requires explicit looping through the array, which can be slow for large datasets.
		- Conditional checks can lead to performance issues if not optimized.
* **FindIndex Library Function:**
	+ Pros:
		- Concise and readable code.
		- Abstracts away iteration and conditional checks, making it easier to maintain.
	+ Cons:
		- Additional overhead due to the use of a library function.
		- May be slower than manual loops for very large datasets.

**Library:**
The `findIndex()` function is a built-in JavaScript method that searches for the first occurrence of a value in an array and returns its index. It uses a binary search algorithm under the hood, which makes it efficient for finding indices in arrays with millions of elements.

**Special JS Features or Syntax:**
There are no special features or syntax used in this benchmark beyond the use of the `findIndex()` function.

**Other Considerations:**

When working with large datasets like 6 million elements, it's essential to consider the following factors:

* **Caching:** JavaScript engines often cache the results of previous executions to improve performance. However, caching can also lead to slower execution times if the benchmark is run multiple times.
* **Garbage Collection:** Garbage collection occurs when the engine frees memory occupied by objects that are no longer in use. Frequent garbage collection can slow down applications.

**Alternative Approaches:**

Other approaches for finding indices in an array include:

1. **Binary Search:** This approach uses a divide-and-conquer algorithm to find the index of a value in an array, which is more efficient than manual loops.
2. **Spliced Array Search:** Some JavaScript engines use splicing to improve search performance. However, this approach requires careful consideration of memory allocation and copying.

Keep in mind that the best approach depends on the specific requirements and constraints of your application. The benchmark results provided by MeasureThat.net can help you decide which approach is most suitable for your needs.

Related benchmarks:

Loops of loops VS. Manual Loops (version: 1)

Comparing performance of: All finds in one loop vs Manual finds with multiple loops

Created: 8 years ago by: Registered User

Jump to the latest result

All finds in one loop

Manual finds with multiple loops

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):