Benchmark: Map get VS Map has get - KShitij

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, {
  "compilerOptions": {
    "lib": ["esnext", "dom"],
    "target": "esnext",
    "esModuleInterop": true,
    "resolveJsonModule": true,
    "strict": true,
    "moduleResolution": "node",
    "noEmit": true
  }
}
);
  }
}

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.

**Benchmark Overview**

The provided benchmark, "Map get VS Map has get - KShitij", is designed to compare the performance of two approaches when retrieving values from a Map data structure in JavaScript: `map.get()` and `map.has()`. The benchmark is intended to measure which approach is faster for small, random keys.

**Options Compared**

The benchmark compares two options:

1. **`map.get(i)`**: This method retrieves the value associated with the key `i` from the Map. It returns `undefined` if the key does not exist.
2. **`if (map.has(i)) { a = map.get(i); }`**: This approach first checks if the key exists in the Map using the `has()` method, and only then retrieves the value using `get()`. If the key does not exist, the expression is short-circuited, and the value of `a` remains `undefined`.

**Pros and Cons**

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

Pros:

* Simple and straightforward
* No additional overhead for checking if a key exists

Cons:

* If the key does not exist, it returns `undefined`, which may lead to unnecessary computations downstream.
* May be slower if the Map is large or if many keys are missing.

**`if (map.has(i)) { a = map.get(i); }`**

Pros:

* Avoids the issue of returning `undefined`
* More efficient when many keys are missing, as it short-circuits the expression

Cons:

* Adds an extra step for checking if the key exists
* May be slower for small Maps or when most keys exist.

**Other Considerations**

The benchmark uses a random distribution of keys to ensure that both approaches perform equally well in different scenarios. The use of `Math.random()` to generate random keys helps to isolate any performance differences between the two approaches.

**Library and Special JS Features**

In this benchmark, there is no explicit mention of any libraries or special JavaScript features beyond standard ES6 syntax.

**Alternatives**

If you were to design an alternative benchmark for Map lookups, you might consider exploring other optimization strategies, such as:

* Using a more efficient data structure, like a HashTable or a custom implementation with caching.
* Optimizing the JavaScript engine used by the benchmark (e.g., V8 in Chrome).
* Measuring the impact of using `Map.prototype.set()` instead of `map.set(i)` on performance.

However, for this specific comparison between `map.get()` and `if (map.has(i)) { a = map.get(i); }`, the above pros and cons analysis should provide sufficient insight into the trade-offs involved.

Related benchmarks:

Map get VS Map has get - KShitij (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):