Benchmark: Map get VS Map has get3

Script Preparation code:

var i = 0, count = 200000, a;
var map = new Map();

for (i = 0; i < count; i++) {
   map.set(i + '_' + '_g' , i);
}

Tests:

Map get
for (i = 0; i < count; i++) { a = map.get(i + '_' + '_g'); }
Map has get
for (i = 0; i < count; i++) { let key = i + '_' + '_g'; if (map.has(key)) { a = map.get(key); } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map get
Map has get

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.

I'll break down the provided benchmark definition and test cases to explain what's being tested, compare different approaches, and discuss pros and cons.

**Benchmark Definition**

The benchmark is designed to measure the performance of two ways to retrieve values from a `Map` object in JavaScript:

1. Using the `get()` method: `map.get(i + '_' + '_g')`
2. Using the `has()` method followed by `get()`: `if (map.has(key)) { a = map.get(key); }`

**Script Preparation Code**

The script preparation code creates a new `Map` object named `map` and populates it with 200,000 key-value pairs using the `set()` method.

```javascript
var i = 0, count = 200000, a;
var map = new Map();

for (i = 0; i < count; i++) {
  map.set(i + '_' + '_g', i);
}
```

**Html Preparation Code**

The html preparation code is empty (`null`), which means the benchmark doesn't involve any additional HTML setup or parsing.

**Individual Test Cases**

There are two test cases:

1. **Map get**
```javascript
for (i = 0; i < count; i++) {
  a = map.get(i + '_' + '_g');
}
```

This test case uses the `get()` method to retrieve values from the `map` object.

2. **Map has get**
```javascript
for (i = 0; i < count; i++) {
  let key = i + '_' + '_g';
  if (map.has(key)) {
    a = map.get(key);
  }
}
```

This test case uses the `has()` method to check if a key exists in the `map` object, and then retrieves the value using the `get()` method.

**Comparison of Approaches**

The two approaches have different pros and cons:

* **Map get**: This approach is likely to be faster because it directly accesses the value associated with a key without checking for its existence. However, it may not work correctly if the key is not present in the map.
* **Map has get**: This approach first checks if a key exists using `has()`, which can be slower than directly accessing the value. However, it ensures that the key is present before attempting to retrieve its value.

**Library and Purpose**

In this benchmark, there are no libraries used beyond the built-in `Map` object in JavaScript.

**Special JS Feature or Syntax**

The `has()` method was introduced in ECMAScript 2015 (ES6) as part of the standard. It's a convenient way to check if a key exists in an object without using the `in` operator or bracket notation (`[key]`).

**Other Alternatives**

There are alternative ways to retrieve values from a map-like object, such as:

* Using the `get()` method with a default value (e.g., `map.get(key) || defaultValue`)
* Using a custom function to check for key existence and retrieve the value
* Using a different data structure, such as an array or object, to store the key-value pairs.

In general, the choice of approach depends on the specific use case and performance requirements.

Related benchmarks:

Map get VS Map has get3 (version: 0)

Map get VS Map has get2

Comparing performance of: Map get vs Map has get

Created: 3 years ago by: Guest

Jump to the latest result

Map get

Map has get

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):