Benchmark: Map get VS Map has get (fork)

Script Preparation code:

var i = 0, count = 1000, a;
var map = new Map();

for (i = 0; i < count; i++) {
  if (Math.random() > 0.5) {
    map.set(i, i * i);
  }
}

Tests:

Map 1
for (i = 0; i < count; i++) { a = map.has(i); }
Map 2
for (i = 0; i < count; i++) { a = map.get(i); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map 1
Map 2

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/111.0.5563.101 Mobile/15E148 Safari/604.1

Browser/OS: Chrome Mobile iOS 111 on iOS 16.3

View result in a separate tab

Test name	Executions per second
Map 1	5669.4 Ops/sec
Map 2	5651.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Overview**

The provided JSON represents two individual test cases for measuring the performance difference between `Map.get()` and `Map.has()`. The benchmark is designed to compare these two methods in terms of execution speed on a map data structure.

**Options Compared**

Two options are compared:

1. `Map.get(i)`: This method retrieves the value associated with a given key (`i`) from the map.
2. `Map.has(i)`: This method checks if a key is present in the map without retrieving its value.

**Pros and Cons of Each Approach**

*   **`Map.get(i)`**: This approach involves retrieving the value associated with each key. If the key exists, it returns the corresponding value; otherwise, it returns `undefined`.
    *   Pros:
        *   Directly retrieves the desired value.
        *   Efficient if the key is present in the map.
    *   Cons:
        *   Inefficient if the key is not present in the map (returns `undefined`).
        *   May incur additional memory usage due to storing keys and values.

*   **`Map.has(i)`**: This approach involves checking if a key exists without retrieving its value. It returns a boolean indicating whether the key is present.
    *   Pros:
        *   Efficient as it only checks for existence, regardless of presence.
        *   Reduces memory usage since no keys or values are stored.

*   **Performance Considerations**: Since `Map.has(i)` involves checking for existence without retrieving values, it generally outperforms `Map.get(i)` when the key is not present. However, if the key exists and its value needs to be retrieved, `Map.get(i)` might provide better performance due to direct access.

**Library Usage**

There is no explicit library usage mentioned in the provided JSON. Both `Map.get()` and `Map.has()` are native JavaScript methods.

**Special JS Feature/Syntax**

No special JavaScript features or syntax are used in this benchmark.

**Alternative Approaches**

Some alternative approaches could be explored:

*   **Using a Set instead of a Map**: If you only need to check for existence without retrieving values, using a `Set` data structure might provide better performance. However, if you need to store key-value pairs, a `Map` is still the most suitable choice.
*   **Caching Results**: To further optimize performance, you could cache the results of `Map.has(i)` or `Map.get(i)` for repeated executions on the same iteration index.
*   **Using Optimized JavaScript Engines**: The choice of JavaScript engine and its optimizations can impact benchmark results. Some engines might provide better performance for certain operations.

By understanding these nuances, developers can make informed decisions about optimizing their code's performance in various scenarios.

Related benchmarks:

Map get VS Map has get (fork) (version: 0)

Map get VS Map has get

Comparing performance of: Map 1 vs Map 2

Created: one year ago by: Guest

Jump to the latest result

Map 1

Map 2

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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