Benchmark: indexOf vs map - MeasureThat.net

Script Preparation code:

var array = [];
for (var i=0; i<100; ++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) { hasWithIndexOf('404'); }
map
for (var i=0; i<100; ++i) { hasWithMap('404'); }

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:

Run details: (Test run date: 4 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:146.0) Gecko/20100101 Firefox/146.0

Browser/OS: Firefox 146 on Windows

View result in a separate tab

Test name	Executions per second
indexOf	121239.3 Ops/sec
map	25637662.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definition and test cases to help explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark is defined using JavaScript, which will be executed on different browsers and platforms. The script preparation code creates an array of strings with a specific format (`"00" + i`) and two functions:

1. `hasWithIndexOf(needle)`: Checks if the given `needle` exists in the array by searching for its index using `array.indexOf(needle)`.
2. `hasWithMap(needle)`: Creates a map from the array elements (using `forEach`) and checks if the `needle` is present in the map using the `in` operator.

**Comparison**

The benchmark compares two approaches:

1. **IndexOf**: The `indexOf` function searches for the presence of the `needle` element in the array.
2. **Map**: A map is created from the array elements, and then a check is performed to see if the `needle` is present in the map.

**Pros and Cons**

*   **IndexOf Approach**
    *   Pros:
        *   Simple and straightforward implementation.
        *   Fast lookup times for large datasets.
    *   Cons:
        *   May have performance issues when dealing with very large arrays due to the search algorithm's time complexity (O(n)).
*   **Map Approach**
    *   Pros:
        *   Efficient use of memory, as the map only stores unique values.
        *   Fast lookup times for large datasets, thanks to the hash table data structure used by maps.
    *   Cons:
        *   May have a higher overhead due to the need to create and populate the map.

**Library**

In this benchmark, no external libraries are explicitly mentioned. However, if we consider the use of JavaScript's built-in `Array.prototype.forEach` method, it's worth noting that this method is implemented in native code by modern JavaScript engines, making it relatively fast compared to equivalent library-based solutions.

**Special JS Feature/Syntax**

In this benchmark, there is no explicit mention of any special JavaScript features or syntax. However, the use of `var`, `let`, and `const` declarations, as well as the `in` operator for checking map presence, are all standard JavaScript constructs that are widely supported across different browsers and platforms.

**Other Alternatives**

For comparing search algorithms in larger datasets, other approaches could include:

1.  **Hash Table**: Implementing a custom hash table data structure using JavaScript's built-in `Object` or similar primitives to compare the performance of different lookup methods.
2.  **Binary Search**: Utilizing binary search algorithms for searching elements within sorted arrays to evaluate their efficiency in comparison with the provided `indexOf` and map-based approaches.
3.  **Regular Expressions**: Exploring the use of regular expressions (regex) for pattern matching, as they can often provide faster lookup times than string manipulation functions like `indexOf`.
4.  **Native Code Implementations**: Investigating native code implementations of search algorithms using languages that are optimized for performance and memory efficiency, such as C++ or Rust.

In conclusion, the provided benchmark compares the basic JavaScript `indexOf` function with a map-based approach to search for elements within an array. Understanding the trade-offs between these two methods can help developers choose the most suitable solution depending on their specific use case and requirements.

Related benchmarks:

indexOf vs map (version: 0)

Comparing performance of: indexOf vs map

Created: 8 years ago by: Guest

Jump to the latest result

indexOf

map

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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