Benchmark: IndexOf vs for loop

Script Preparation code:

window.largeArray = [];
const largeNumber = 5000;

for (let i = 0; i < largeNumber; i++) {
  largeArray.push(i);
}

function removeNumberWithIndexOf(array, number) {
  array.splice(array.indexOf(number), 1);
}

function removeNumberWithForLoop(array, number) {
  for (let k = 0, kl = array.length; k < kl; k++) {
    if (number === array[k]) {
      array.splice(k, 1);
    }
  }
}

Tests:

IndexOf
removeNumberWithIndexOf(largeArray, 5); removeNumberWithIndexOf(largeArray, 128); removeNumberWithIndexOf(largeArray, 42); removeNumberWithIndexOf(largeArray, 4800); removeNumberWithIndexOf(largeArray, 2000); removeNumberWithIndexOf(largeArray, 2650);
For loop
removeNumberWithForLoop(largeArray, 5); removeNumberWithForLoop(largeArray, 128); removeNumberWithForLoop(largeArray, 42); removeNumberWithForLoop(largeArray, 4800); removeNumberWithForLoop(largeArray, 2000); removeNumberWithForLoop(largeArray, 2650);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
IndexOf
For loop

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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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 explain what is being tested.

**Benchmark Definition**

The benchmark definition is a JSON object that describes two test cases: `removeNumberWithIndexOf` and `removeNumberWithForLoop`. Both functions are designed to remove specific numbers from an array using different methods. The main difference between the two functions lies in how they perform the removal:

* `removeNumberWithIndexOf`: Uses the built-in `indexOf()` method of arrays to find the index of the target number, then uses the `splice()` method to remove it.
* `removeNumberWithForLoop`: Iterates through the array manually using a for loop, checking each element to see if it matches the target number. If a match is found, the corresponding element is removed from the array.

**Options Compared**

The two options being compared are:

1. Using `indexOf()` method to remove an element (in `removeNumberWithIndexOf`)
2. Iterating through an array manually using a for loop (in `removeNumberWithForLoop`)

**Pros and Cons of Each Approach**

* **Using `indexOf()` method**: Pros:
	+ Faster, as it uses a built-in optimization under the hood.
	+ More concise code.
	+ Less chance of off-by-one errors or index out-of-range issues.
* Cons:
	+ May not work well for very large arrays due to performance issues with `splice()`.
	+ Requires the target element to be present in the array; if not, it will return -1 and the removal won't happen.
* **Iterating through an array manually**: Pros:
	+ Works well for very large arrays, as it doesn't rely on internal array methods that can become slow.
	+ Allows for more control over the iteration process.
	+ Does not require the target element to be present in the array; if not, the loop will simply skip over it.

Cons:

* More verbose code.
* Higher chance of off-by-one errors or index out-of-range issues.
* Can be slower for small arrays due to the overhead of manual iteration.

**Library Used**

The `splice()` method used in `removeNumberWithIndexOf` is a built-in array method, not an external library. It's available on most modern browsers and Node.js environments.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntax used in this benchmark that would require additional explanation beyond the scope of this answer.

**Alternatives**

If you're interested in exploring alternative approaches to remove elements from an array, some options could be:

* Using `filter()` method: This method creates a new array with all elements that pass the test implemented by the provided function.
* Using `map()` method and then combining results: You can use `map()` to create a new array with modified values and then combine the results using a different approach, like filtering or concatenating arrays.

However, these alternatives might not be as straightforward for this specific use case, and their performance would likely vary depending on the size of the array and the browser/environment.

Related benchmarks:

IndexOf vs for loop (version: 0)

Comparing performance of: IndexOf vs For loop

Created: 3 years ago by: Registered User

Jump to the latest result

IndexOf

For loop

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):