Benchmark: Map get VS Map has get

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.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:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36

Browser/OS: Chrome 145 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Map 1	7994.2 Ops/sec
Map 2	11353.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Definition**

The test measures the performance difference between two approaches:

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

These approaches are used to retrieve a value from a Map data structure in JavaScript.

**Options Compared**

We have two options being compared:

A) Using `map.get(i)` directly
B) Using `if (map.has(i))` followed by `map.get(i)`

**Pros and Cons of Each Approach:**

1. **Direct `map.get(i)`**
	* Pros:
		+ Simple and concise syntax.
		+ Fast, as it uses a direct index lookup.
	* Cons:
		+ May not be as efficient if the Map is very large or has many keys with values that need to be checked.
2. **`if (map.has(i)) ... map.get(i)`**
	* Pros:
		+ Allows for optional checking of whether the key exists in the Map before retrieving its value.
		+ Can be useful when you want to handle cases where the key might not exist.
	* Cons:
		+ Slightly slower than direct `map.get(i)`, due to the additional check.

**Library and Purpose**

In this benchmark, there is no specific library being used. However, it's worth noting that Map data structures are a part of the ECMAScript standard, which means they're built into JavaScript engines by default.

**Special JS Feature or Syntax**

There is no special JavaScript feature or syntax being tested in this benchmark. It only involves standard JavaScript operations and data structures.

**Other Alternatives**

If you wanted to test different approaches to retrieving values from a Map, some alternative options might include:

* Using `map.get(i)` with caching (e.g., using an object to store the results of previous lookups)
* Using `map.has(i)` followed by another operation (e.g., using `map.get()` on a related data structure)
* Comparing different implementations or libraries for Map operations (e.g., V8 vs. SpiderMonkey)
* Testing other data structures, such as Arrays or Objects, for similar operations

Keep in mind that these alternatives would require significant changes to the benchmark setup and test cases.

I hope this explanation helps!

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: 3 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):