Benchmark: Map vs Object - MeasureThat.net

Script Preparation code:

var map = new Map();
var obj = {};

map.set('a', 5);
obj['a'] = 5;

var i = 0, count = 1000, a;

Tests:

Map lookup
for (i = 0; i < count; i++) { a = map.get('a'); }
Obj lookup
for (i = 0; i < count; i++) { a = obj['a']; }

Historical Performance Data aggregated from 164 community runs

Desktop Results:

Chrome 115 runs

Obj lookup

8K/s

Map lookup

7K/s

View exact numbers

✓ Obj lookup: 7,753 ops/sec
• Map lookup: 7,198 ops/sec

Firefox 28 runs

Obj lookup

66K/s

Map lookup

56K/s

Fastest: Obj lookup (1.2x faster)

View exact numbers

✓ Obj lookup: 66,399 ops/sec
• Map lookup: 55,921 ops/sec

Safari 10 runs

Obj lookup

11K/s

Map lookup

11K/s

View exact numbers

✓ Obj lookup: 10,821 ops/sec
• Map lookup: 10,685 ops/sec

Mobile Results:

Chrome 6 runs

Obj lookup

3K/s

Map lookup

3K/s

View exact numbers

✓ Obj lookup: 3,358 ops/sec
• Map lookup: 3,112 ops/sec

Safari 5 runs

Obj lookup

4K/s

Map lookup

4K/s

View exact numbers

✓ Obj lookup: 4,446 ops/sec
• Map lookup: 4,399 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
Map lookup
Obj lookup

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36

Browser/OS: Chrome 148 on Linux

View result in a separate tab

Obj lookup

436/s

Map lookup

228/s

View exact numbers

Test name	Executions per second
✓ Obj lookup	436 Ops/sec
Map lookup	228 Ops/sec

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 and explain what is being tested, compared, and the pros/cons of each approach.

**Benchmark Definition: Map vs Object**

The benchmark measures the performance difference between looking up values in a `Map` object versus an `Object`. A `Map` is a data structure that stores key-value pairs, whereas an `Object` is a general-purpose data type in JavaScript that can store any number of key-value pairs.

**Script Preparation Code**
```javascript
var map = new Map();
var obj = {};
map.set('a', 5);
obj['a'] = 5;
```
This code creates two objects: `map` and `obj`. It then sets a value for the key `'a'` in both objects using the `set()` method for `Map` and the bracket notation `[]` for `Object`.

**Html Preparation Code**

The `Html Preparation Code` is empty, which means that this benchmark does not test any HTML-related performance.

**Individual Test Cases: Map Lookup and Object Lookup**

There are two test cases:

1. **Map Lookup**: This test case measures the time it takes to iterate 1000 times over the map and look up the value for the key `'a'` using the `get()` method.
2. **Object Lookup**: This test case measures the time it takes to iterate 1000 times over the object and look up the value for the key `'a'` using the bracket notation `[]`.

**Library Used: None**

Neither of these test cases uses any external libraries.

**Special JS Feature/Syntax: None**

There are no special JavaScript features or syntax used in this benchmark.

**Pros and Cons:**

* **Map Lookup**: Using a `Map` object can be beneficial if you need to look up values by key multiple times, as it provides faster lookup times compared to `Object`. However, creating a `Map` object requires additional memory and may not be suitable for all use cases.
* **Object Lookup**: Using an `Object` is more straightforward and widely supported. It can also be useful if you need to store arbitrary data in the object.

**Other Alternatives:**

If you needed to compare other data structures, such as:

* Arrays vs Objects
* Sets vs Arrays
* Maps vs Sets

You could create similar benchmarks using different script preparation codes and test cases.

For example, to benchmark arrays vs objects, you could use:
```javascript
var arr = [];
var obj = {};
for (i = 0; i < count; i++) {
  arr.push(i);
  obj[i] = i;
}
```
This would measure the time it takes to iterate over an array and add elements versus iterating over an object and setting properties.

Similarly, you could benchmark sets vs arrays or maps vs sets using different script preparation codes and test cases.

Map vs Object (version: 0)

Lookup of map vs object

Comparing performance of: `Map lookup vs Obj lookup`

Created: 9 years ago by: Registered User

Go to the latest result

Map lookup

Obj lookup

Historical Performance Data aggregated from 164 community runs

Desktop Results:

Chrome 115 runs

Firefox 28 runs

Safari 10 runs

Mobile Results:

Chrome 6 runs

Safari 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Map vs Object (version: 0)

Lookup of map vs object

Comparing performance of: Map lookup vs Obj lookup

Created: 9 years ago by: Registered User

Go to the latest result

Map lookup

Obj lookup

Historical Performance Data aggregated from 164 community runs

Desktop Results:

Chrome 115 runs

Firefox 28 runs

Safari 10 runs

Mobile Results:

Chrome 6 runs

Safari 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `Map lookup vs Obj lookup`