Benchmark: indexOf vs map - MeasureThat.net

Script Preparation code:

function hasWithIndexOf(needle, haystack) {
	return haystack.indexOf(needle) !== -1;
}

function hasWithMap(needle, haystackMap) {
	return haystackMap[needle];
}


function prepareMap(haystack) {
	var map = {};
	for (var i=0, len=haystack.length; i<len; ++i) {
    	map[haystack[i]] = true;
    }
    return map;
}
  
         
var haystack = [];
for (var i=0; i<100; ++i) {
  	haystack.push('00' + i);
}

var haystackMap = prepareMap(haystack);

Tests:

indexOf
for (var i=0; i<100; ++i) { hasWithIndexOf('404', haystack); }
map new each pass
var haystackMapLocal = prepareMap(haystack); for (var i=0; i<100; ++i) { hasWithMap('404', haystackMapLocal); }
map cached
for (var i=0; i<100; ++i) { hasWithMap('404', haystackMap); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
indexOf
map new each pass
map cached

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 definition and test cases to understand what's being tested.

**Benchmark Definition**

The benchmark defines two functions, `hasWithIndexOf` and `hasWithMap`, which are used to check if a specific string (`"404"`) exists in an array of strings (`"00" + i`). The `prepareMap` function is also defined to create a map from the haystack array.

**Options Compared**

The benchmark compares three options:

1. **`indexOf`**: Using the `indexOf` method on the haystack array.
2. **`map new each pass`**: Creating a new map for each iteration of the loop and using it to look up the value.
3. **`map cached`**: Reusing the same map created by `prepareMap` across all iterations of the loop.

**Pros and Cons**

Here's a brief summary of each option:

* **`indexOf`**: Fastest, but may not be optimized for performance in modern browsers. It's also limited to searching for exact matches.
	+ Pros: Simple, widely supported, and easy to implement.
	+ Cons: May have overhead due to browser optimizations or caching.
* **`map new each pass`**: Creates a new map on each iteration, which can lead to slower performance due to the overhead of creating a new object.
	+ Pros: Allows for more flexibility in the implementation, as the map can be reused or replaced if needed.
	+ Cons: Can lead to slower performance and increased memory usage.
* **`map cached`**: Reuses the same map created by `prepareMap`, which can improve performance by reducing the overhead of creating a new object on each iteration.
	+ Pros: Can provide better performance, especially for larger datasets or repeated searches.
	+ Cons: May lead to slower initialization times due to the need to create and cache the initial map.

**Libraries**

In this benchmark, there is no explicit library mentioned. However, it's worth noting that `prepareMap` function is creating a simple JavaScript object map using an array of values as keys, which is a basic implementation of a hash table.

**Special JS Features/Syntax**

There are no special JavaScript features or syntaxes being tested in this benchmark. The code uses standard ECMAScript syntax and does not rely on any advanced features like async/await, promises, or experimental APIs.

**Other Alternatives**

If the `indexOf` method is not sufficient, other alternatives could include:

* Using a library like Lodash or Ramda for more functional programming approaches.
* Implementing a custom hash table data structure using JavaScript's built-in objects and methods.
* Utilizing browser-specific features like Web Workers or WebAssembly for parallel processing.

Keep in mind that these alternatives may introduce additional complexity, overhead, or dependencies, which should be carefully considered when choosing an approach.

Related benchmarks:

indexOf vs map (version: 0)

Comparing performance of: indexOf vs map new each pass vs map cached

Created: 9 years ago by: Guest

Jump to the latest result

indexOf

map new each pass

map cached

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):