Benchmark: set.add vs array.push vs map.set

Script Preparation code:

var array = [];
var set = new Set();
var map = new Map();

var existingItem1 = {};
var existingItem2 = {};
var existingItem3 = {};
var newItem1 = {};
var newItem2 = {};
var newItem3 = {};

for (let i = 0, item; i < 100; i++) {
  item = {index: i};
  array.push(item);
  set.add(item);
  map.set(item, 0);
}

array.push(existingItem1, existingItem2, existingItem3);
set.add(existingItem1); set.add(existingItem2); set.add(existingItem3);
map.set(existingItem1, 0); map.set(existingItem2, 0); map.set(existingItem3, 0);

Tests:

conditional array.push
if (!array.includes(existingItem1)) { array.push(existingItem1); } if (!array.includes(newItem1)) { array.push(newItem1); } if (!array.includes(existingItem2)) { array.push(existingItem2); } if (!array.includes(newItem2)) { array.push(newItem2); } if (!array.includes(existingItem3)) { array.push(existingItem3); } if (!array.includes(newItem3)) { array.push(newItem3); }
set.add
set.add(existingItem1); set.add(newItem1); set.add(existingItem2); set.add(newItem2); set.add(existingItem3); set.add(newItem3);
map.set overwrite
map.set(existingItem1, 0); map.set(newItem1, 0); map.set(existingItem2, 0); map.set(newItem2, 0); map.set(existingItem3, 0); map.set(newItem3, 0);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
conditional array.push
set.add
map.set overwrite

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 16 days ago)

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 135 on Android

View result in a separate tab

Test name	Executions per second
conditional array.push	6586352.5 Ops/sec
set.add	20081644.0 Ops/sec
map.set overwrite	18038232.0 Ops/sec

Autogenerated LLM Summary (model llama3.1:latest, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's dive into the benchmark test cases provided.

**Benchmark Description**

The benchmark is comparing three different methods to add items to a collection: `array.push`, `set.add`, and `map.set`. The test case generates 100 unique items and then adds an additional 3 existing items (existingItem1, existingItem2, existingItem3) to the collection using each of these methods. The benchmark measures how many executions per second each method can handle.

**Test Cases**

There are three individual test cases:

1. **"conditional array.push"**: This test case uses an `if` statement to check if an item already exists in the array before pushing it. If it doesn't exist, it's added to the array.
2. **"set.add"**: This test case simply adds existing items and new items to a Set data structure using the `add` method.
3. **"map.set overwrite"**: This test case sets values for existing items in a Map data structure using the `set` method, effectively overwriting any previous value.

**Library/Feature Used**

None of these test cases use any external libraries or special JavaScript features beyond what's built-in to modern browsers (e.g., Sets and Maps).

**Options Compared**

The benchmark is comparing three different methods:

* **array.push**: Adding items directly to an array using the `push` method.
* **set.add**: Using a Set data structure with the `add` method to add unique items.
* **map.set**: Using a Map data structure with the `set` method to store key-value pairs, effectively allowing overwriting of previous values.

**Pros/Cons**

Here are some pros and cons for each method:

* **array.push**:
	+ Pros: Simple implementation, fast array access and manipulation.
	+ Cons: May have poor cache locality if items are sparse or not stored contiguously.
* **set.add**:
	+ Pros: Efficient storage of unique items, fast lookup times (average O(1)).
	+ Cons: Not suitable for storing non-unique data or values.
* **map.set**:
	+ Pros: Allows efficient storage and retrieval of key-value pairs with average time complexity of O(1).
	+ Cons: May incur overhead due to hash computation and collision resolution.

**Other Considerations**

When choosing an implementation, consider the specific use case:

* If you need to store a large number of unique items and fast lookup is essential (e.g., in a cache or for fast membership testing), a Set might be a good choice.
* For storing key-value pairs where overwriting existing values is acceptable, a Map could be suitable.
* When working with arrays where cache locality and simple iteration are important (e.g., iterating over an array of items), `array.push` may be the way to go.

**Alternatives**

Other alternatives for similar use cases include:

* Using a **Hash Table**, which can provide average time complexity of O(1) for insertions, deletions, and lookups.
* Employing a more advanced data structure like a **Trie** or **Prefix Tree**, suitable for storing complex hierarchies or strings with efficient lookup and insertion.

That's it! This explanation should help you understand the benchmark test cases provided.

Related benchmarks:

set.add vs array.push vs map.set (version: 0)

Comparing performance of: conditional array.push vs set.add vs map.set overwrite

Created: 3 years ago by: Guest

Jump to the latest result

conditional array.push

set.add

map.set overwrite

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated 6 months ago):