Benchmark: Map get VS Map has get part 2

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
let b; for (i = 0; i < count; i++) { a = map.get(i); if (a) { b = a; } }
Map 2
let b; for (i = 0; i < count; i++) { if (map.has(i)) { b = 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 (X11; Linux x86_64; rv:133.0) Gecko/20100101 Firefox/133.0

Browser/OS: Firefox 133 on Linux

View result in a separate tab

Test name	Executions per second
Map 1	57938.0 Ops/sec
Map 2	61088.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what is being tested in this benchmark and the pros/cons of different approaches.

**Benchmark Definition**

The benchmark measures the performance difference between two ways to retrieve values from a `Map` object:

1. Using `map.get()`
2. Using `map.has()` followed by `map.get()`

**Script Preparation Code**

The script creates a new `Map` object and populates it with 1000 key-value pairs, where each value is the square of its corresponding key.

**Html Preparation Code**

There is no HTML preparation code provided, so we'll focus on the JavaScript aspects only.

**Individual Test Cases**

We have two test cases:

1. **Test Case "Map 1"**
```javascript
let b;
for (i = 0; i < count; i++) {
  a = map.get(i);
  if (a) {
    b = a;
  }
}
```
This code uses `map.get()` to retrieve the value associated with each key and assigns it to `b` only if the value is not null or undefined.

2. **Test Case "Map 2"**
```javascript
let b;
for (i = 0; i < count; i++) {
  if (map.has(i)) {
    b = map.get(i);
  }
}
```
This code uses `map.has()` to check if each key exists in the map and then uses `map.get()` to retrieve its value, assigning it to `b`.

**Pros/Cons of Different Approaches**

1. **`map.get()`**
	* Pros: Simple and efficient for most use cases.
	* Cons: If the key is not found, it will return `undefined`, which can lead to unnecessary iterations in some cases.
2. **`map.has()` followed by `map.get()`
	* Pros: Ensures that the key exists before attempting to retrieve its value, avoiding null or undefined values.
	* Cons: Requires an additional iteration, potentially leading to slower performance.

**Library and Purpose**

In this benchmark, no external libraries are used. The `Map` object is a built-in JavaScript data structure.

**Special JS Features/Syntax**

None of the test cases use any special JavaScript features or syntax that would affect their execution.

**Other Alternatives**

If you wanted to test alternative approaches, you could consider:

* Using `Object.keys()` and `at()` (ECMAScript 2022) to iterate over map entries
* Using a custom function to check if the key exists in the map before retrieving its value
* Comparing the performance of different map implementations, such as `Map` vs. `WeakMap`
* Measuring the impact of using `map.get()` vs. `map.has()` on memory usage or other factors

Keep in mind that these alternatives might not be directly relevant to the specific use case being tested and may introduce additional complexity.

Related benchmarks:

Map get VS Map has get part 2 (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

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