Benchmark: indexOf vs map 002-10

Script Preparation code:

var array = [];
for (var i=0; i<10; ++i) {
  	array.push('00' + i);
}

function hasWithIndexOf(needle) {
	return array.indexOf(needle) !== -1;
}

var map = {};
array.forEach(item => map[item] = true);

function hasWithMap(needle) {
	return needle in map;
}

Tests:

indexOf
for (var i=0; i<100; ++i) { array.indexOf("404") !== -1; // array.indexOf("000") !== -1; }
map
for (var i=0; i<100; ++i) { const x = "404" in map }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
indexOf
map

Fastest: N/A

Slowest: N/A

Latest run results:

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

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

**Benchmark Overview**

The benchmark measures the performance of two different approaches to check if an element exists in an array: `indexOf` and `map`. The test creates an array with 10 elements, each represented as a string `00` followed by a zero digit (e.g., "00", "01", ..., "09"). Two functions are defined:

1. `hasWithIndexOf(needle)`: uses the `indexOf` method to check if the needle is present in the array.
2. `hasWithMap(needle)`: creates a map with all elements of the array as keys and assigns `true` to each key using the `forEach` method.

**Options Compared**

The two options being compared are:

1. **`indexOf`**: uses the `indexOf` method, which searches for the first occurrence of the specified value in the array.
2. **`map`**: creates a map with all elements of the array as keys and assigns `true` to each key.

**Pros and Cons**

* **`indexOf`**:
	+ Pros:
		- Simple and efficient (O(1) average-case performance).
		- Widely supported across browsers.
	+ Cons:
		- May not be suitable for large datasets, as it can lead to slower performance due to the search algorithm.
		- Can throw an error if the needle is not found in the array.
* **`map`**:
	+ Pros:
		- Suitable for large datasets, as it creates a new data structure that allows for efficient lookups (O(1) average-case performance).
		- Can be more readable and easier to maintain than `indexOf`, especially when working with complex conditions.
	+ Cons:
		- Requires creating an additional data structure (the map), which can lead to higher memory usage.
		- May not be as efficient as `indexOf` for small datasets.

**Library: `forEach`**

The `forEach` method is a part of the ECMAScript standard and is used to iterate over an array and execute a callback function for each element. In this benchmark, it's used to create the map by iterating over the array and assigning `true` to each key.

**Special JavaScript Feature: None mentioned**

No special JavaScript features or syntax are being tested in this benchmark.

**Other Alternatives**

If you need to check if an element exists in an array, other alternatives include:

* Using a library like Lodash's `findIndex`, which provides a more efficient and flexible way of searching arrays.
* Creating a custom search function using a binary search algorithm, which can be more efficient for large datasets.
* Using a data structure like a Set or a Map, which provide faster lookup times than arrays.

Keep in mind that the choice of approach depends on the specific use case, dataset size, and performance requirements.

Related benchmarks:

indexOf vs map 002-10 (version: 0)

Comparing performance of: indexOf vs map

Created: 2 years ago by: Guest

Jump to the latest result

indexOf

map

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):