Benchmark: Map get VS Map has get!!!

Script Preparation code:

var i = 0, count = 30000, 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.get(i); }
Map 2
for (i = 0; i < count; i++) { if (map.has(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:

No previous run results

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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 its pros and cons.

**Benchmark Definition**

The benchmark measures the performance of two different approaches to accessing values in a Map data structure:

1. `map.get(i)`
2. `if (map.has(i)) { ... } map.get(i)`

The script preparation code creates a large Map with 30,000 entries, where half of the entries are set using `map.set()` and the other half are not.

**Options Compared**

The two options being compared are:

1. **Direct access**: Using `map.get(i)` to directly access a value in the Map.
2. **Indirect access with has()**: Using `if (map.has(i)) { ... } map.get(i)` to first check if a key exists in the Map before accessing its value.

**Pros and Cons**

**Direct Access (`map.get(i)`)**

Pros:

* Faster, as it directly accesses the value without checking for existence.
* Less overhead, as it avoids the `has()` method call.

Cons:

* May throw an error if the key is not found in the Map, which can be a performance bottleneck.

**Indirect Access with has()**

Pros:

* Avoids potential errors by not throwing exceptions if the key is not found.
* Can provide better cache locality, as the `has()` method returns immediately if the key exists.

Cons:

* Slower, due to the additional overhead of checking for existence before accessing the value.
* May incur more memory usage, as the Map needs to keep track of the keys that are checked using `has()`

**Library and Special Features**

The benchmark uses the built-in JavaScript `Map` data structure. No special features or libraries are required.

**Other Considerations**

When testing Map performance, it's essential to consider factors like:

* Cache locality: How often are the same values accessed in a short period?
* Memory allocation: Does the Map allocate memory for each key-value pair?
* Garbage collection: How does the V8 engine (used by Safari) handle garbage collection during the benchmark?

**Alternatives**

Other alternatives to test Map performance might include:

* Using a different data structure, like an object or an array.
* Introducing additional overhead, such as parsing or encoding.
* Testing with smaller or larger datasets.
* Comparing results across different browsers or environments.

Keep in mind that these alternatives should be carefully chosen to ensure they accurately represent the scenarios you want to test.

Related benchmarks:

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

Map get VS Map has get

Comparing performance of: Map 1 vs Map 2

Created: 2 years ago by: Guest

Jump to the latest result

Map 1

Map 2

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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