Benchmark: Map Find 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
for (i = 0; i < count; i++) { a = map.get('a'); }
Object
for (i = 0; i < count; i++) { a = obj['a']; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map
Object

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Map	10880.4 Ops/sec
Object	11132.4 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain the provided benchmark.

**Overview**

The provided JSON represents a JavaScript microbenchmark, which is a small piece of code designed to measure the performance of a specific aspect of JavaScript. The benchmark tests two different approaches: accessing an object property using the bracket notation (`obj['a']`) versus accessing a Map object using the `get` method.

**Options Compared**

The benchmark compares the following two options:

1. **Object Access**: Using the bracket notation to access an object property, i.e., `obj['a']`.
2. **Map Access**: Using the `get` method of a Map object to retrieve a value by its key, i.e., `map.get('a')`.

**Pros and Cons**

*   **Object Access**:
    *   Pros: This approach is generally faster for small to medium-sized objects because it avoids the overhead of a Map object. It's also more intuitive for many developers.
    *   Cons: As the size of the object increases, this approach can become slower due to the need to search the object properties.
*   **Map Access**:
    *   Pros: This approach is generally faster for large datasets because it uses a hash table internally, which allows for constant-time lookups. However, creating and maintaining a Map object can be more memory-intensive than accessing an object property directly.
    *   Cons: This approach requires the use of a Map object, which might be overkill for small to medium-sized objects.

**Library and Special JS Features**

There is no library being used in this benchmark. However, it's worth noting that Maps are a native JavaScript data structure introduced in ECMAScript 2015 (ES6).

**Other Considerations**

*   **Cache**: The benchmark may not account for caching effects on subsequent runs. In real-world scenarios, the results might be different due to cache behavior.
*   ** Garbage Collection**: The benchmark does not take into consideration the potential impact of garbage collection on performance.

**Alternatives**

There are other alternatives to accessing object properties and Map objects:

*   For accessing object properties, you could use `in` operator or bracket notation with a string literal (e.g., `obj['a'] === obj.a`).
*   For Map objects, you could use the `has` method instead of `get` for faster lookups.

Example code:
```javascript
// Using bracket notation and 'in' operator
for (i = 0; i < count; i++) {
    let a = obj['a'] === obj.a ? obj['a'] : obj.a;
}

// Using bracket notation with string literal
for (i = 0; i < count; i++) {
    let a = map.get('a');
}
```

Example code for alternative Map lookup:
```javascript
// Using has method instead of get
for (i = 0; i < count; i++) {
    if (map.has('a')) {
        let a = map.get('a');
    }
}
```

Related benchmarks:

Map Find Object (version: 0)

Comparing performance of: Map vs Object

Created: 4 years ago by: Guest

Jump to the latest result

Map

Object

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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