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);

Historical Performance Data aggregated from 90 community runs

Desktop Results:

Chrome 66 runs

map.set overwrite

2.1M/s

set.add

2.0M/s

conditional array.push

1.8M/s

Fastest: map.set overwrite (1.2x faster)

View exact numbers

✓ map.set overwrite: 2,097,607 ops/sec
• set.add: 2,035,150 ops/sec
• conditional array.push: 1,773,782 ops/sec

Firefox 14 runs

set.add

8.7M/s

map.set overwrite

6.2M/s

conditional array.push

6.2M/s

Fastest: set.add (1.4x faster)

View exact numbers

✓ set.add: 8,688,998 ops/sec
• map.set overwrite: 6,246,049 ops/sec
• conditional array.push: 6,175,460 ops/sec

Safari 5 runs

map.set overwrite

2.7M/s

set.add

2.7M/s

conditional array.push

881K/s

Fastest: map.set overwrite (3.0x faster)

View exact numbers

✓ map.set overwrite: 2,655,609 ops/sec
• set.add: 2,652,681 ops/sec
• conditional array.push: 881,090 ops/sec

Mobile Results:

Safari 5 runs

set.add

2.7M/s

map.set overwrite

2.6M/s

conditional array.push

710K/s

Fastest: set.add (3.8x faster)

View exact numbers

✓ set.add: 2,678,363 ops/sec
• map.set overwrite: 2,616,390 ops/sec
• conditional array.push: 710,244 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

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: 5 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

set.add

10.2M/s

map.set overwrite

6.8M/s

conditional array.push

2.7M/s

View exact numbers

Test name	Executions per second
✓ set.add	10,245,503 Ops/sec
map.set overwrite	6,837,248 Ops/sec
conditional array.push	2,721,112 Ops/sec

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

LLMs can make mistakes. Check important info.

This benchmark tests the performance of three different approaches to adding items to a data structure: using an array with `push`, using a Set with `add`, and using a Map with `set`.

**Here's a breakdown:**

* **`array.push()`**: This method adds an item to the end of an array. It's a common way to add elements to arrays, but it can become slower as the array grows larger.
* **`Set.add()`**: Sets are collections that only store unique values.  The `add()` method efficiently checks for duplicates and only adds new values. This makes it faster than using `array.push()` if you need to ensure uniqueness.
* **`Map.set()`**: Maps associate keys with values. The `set()` method allows you to add or update key-value pairs. It's generally more efficient than arrays for lookups and updates based on a key, but it adds overhead compared to Sets when just focusing on adding new items.

**The benchmark compares these approaches in the following scenarios:**

* **`conditional array.push()`**:  This test simulates adding elements to an array while checking for duplicates using `includes()`. 
* **`set.add()`**: This test directly adds multiple items to a Set.
* **`map.set overwrite`**: This test adds or overwrites key-value pairs in a Map.

**Pros and Cons:**

* **`array.push()`**:  Simple, widely known, but can be slow for large arrays.
* **`Set.add()`**: Fast for adding unique values, efficient memory usage.
* **`Map.set()`**: Powerful for key-value associations, flexible, but can have higher overhead than Sets for simple additions.

**Other Considerations:**

*  **Use Case:** The best choice depends on your specific needs. If you need to ensure uniqueness and prioritize speed, use a Set. For data with inherent keys and values, Maps are ideal. Arrays are suitable when you primarily need sequential access or if performance is not critical.

Let me know if you have any other questions about this benchmark or JavaScript data structures!

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

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

Created: 4 years ago by: Guest

Go to the latest result

conditional array.push

set.add

map.set overwrite

Historical Performance Data aggregated from 90 community runs

Desktop Results:

Chrome 66 runs

Firefox 14 runs

Safari 5 runs

Mobile Results:

Safari 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

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

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

Created: 4 years ago by: Guest

Go to the latest result

conditional array.push

set.add

map.set overwrite

Historical Performance Data aggregated from 90 community runs

Desktop Results:

Chrome 66 runs

Firefox 14 runs

Safari 5 runs

Mobile Results:

Safari 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

Related benchmarks

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