Benchmark: Map get VS Map has get Agag

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);
  }
}

​x
 
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++) {
  if (map.get(i)) {
    a = map.get(i);
  }
}

 
for (i = 0; i < count; i++) {  if (map.get(i)) {    a = map.get(i);  }}

Map 2

for (i = 0; i < count; i++) {
  if (map.has(i)) {
    a = map.get(i);
  }
}

 
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

Experimental features:

Memory measurements supported only in Chrome.
For precise memory measurements Chrome must be launched with --enable-precise-memory-info flag.
More information: Monitoring JavaScript Memory

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 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Map 1	7210.1 Ops/sec
Map 2	7292.9 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

Benchmark Overview

The provided benchmark measures the performance difference between two approaches to retrieving values from a Map data structure in JavaScript: map.get() and map.has(). The test creates a large Map with 1000 entries, where half of the entries have a key-value pair, and then iterates over the map using both approaches to retrieve the value associated with each key.

Approaches Compared

The two approaches compared are:

map.get(i): This approach directly retrieves the value associated with the key i from the Map.
map.has(i) && map.get(i): This approach first checks if the key i exists in the Map using map.has(i), and then retrieves the value using map.get(i). If the key does not exist, this approach will throw a TypeError.

Pros and Cons

map.get(i):
- Pros: Directly retrieves the value associated with the key, which is faster since it only needs to perform a hash lookup.
- Cons: Throws a TypeError if the key does not exist in the Map. This approach assumes that the key exists, which may not always be the case.
map.has(i) && map.get(i):
- Pros: Avoids throwing a TypeError by first checking if the key exists before attempting to retrieve its value.
- Cons: Requires two operations (hash lookup and subsequent retrieval), which can be slower than map.get(i).

Library Usage

There is no explicit library usage in this benchmark. However, JavaScript's built-in Map data structure is used for both approaches.

Special JS Feature/Syntax

None of the test cases use special JavaScript features or syntax beyond standard ECMAScript syntax.

Other Alternatives

If you need to optimize your code for performance and want to avoid the TypeError thrown by map.get(i) when the key does not exist, you could consider using other approaches such as:

Using a separate data structure (e.g., an object or array) to store the keys and their associated values.
Implementing a custom has() method on your Map implementation that returns a boolean indicating whether the key exists, rather than throwing a TypeError.

Keep in mind that these alternatives may have different performance characteristics and trade-offs depending on your specific use case.

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark measures the performance difference between two approaches to retrieving values from a Map data structure in JavaScript: `map.get()` and `map.has()`. The test creates a large Map with 1000 entries, where half of the entries have a key-value pair, and then iterates over the map using both approaches to retrieve the value associated with each key.

**Approaches Compared**

The two approaches compared are:

1. **`map.get(i)`**: This approach directly retrieves the value associated with the key `i` from the Map.
2. **`map.has(i) && map.get(i)`**: This approach first checks if the key `i` exists in the Map using `map.has(i)`, and then retrieves the value using `map.get(i)`. If the key does not exist, this approach will throw a TypeError.

**Pros and Cons**

* **`map.get(i)`**:
	+ Pros: Directly retrieves the value associated with the key, which is faster since it only needs to perform a hash lookup.
	+ Cons: Throws a TypeError if the key does not exist in the Map. This approach assumes that the key exists, which may not always be the case.
* **`map.has(i) && map.get(i)`**:
	+ Pros: Avoids throwing a TypeError by first checking if the key exists before attempting to retrieve its value.
	+ Cons: Requires two operations (hash lookup and subsequent retrieval), which can be slower than `map.get(i)`.

**Library Usage**

There is no explicit library usage in this benchmark. However, JavaScript's built-in Map data structure is used for both approaches.

**Special JS Feature/Syntax**

None of the test cases use special JavaScript features or syntax beyond standard ECMAScript syntax.

**Other Alternatives**

If you need to optimize your code for performance and want to avoid the `TypeError` thrown by `map.get(i)` when the key does not exist, you could consider using other approaches such as:

* Using a separate data structure (e.g., an object or array) to store the keys and their associated values.
* Implementing a custom `has()` method on your Map implementation that returns a boolean indicating whether the key exists, rather than throwing a TypeError.

Keep in mind that these alternatives may have different performance characteristics and trade-offs depending on your specific use case.

Related benchmarks:

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

Map get VS Map has get

Comparing performance of: Map 1 vs Map 2

Created: one year ago by: Guest

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