Benchmark: empty elements - MeasureThat.net

Script Preparation code:

var array1 = [];
array1[1000] = 2;
var array2 = [];
for(i=0; i<=1000; i++){
	array2[i] = 1;
}

Tests:

empty elements
array1.map(item => item)
no empties
array2.map(item => item)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
empty elements
no empties

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The benchmark is designed to measure the performance of the `map()` function in JavaScript, which applies a given function to each element of an array and returns a new array with the results. The test cases are:

1. `empty elements`: An empty array is created (`array1`) and then modified by assigning a value to its 1000th index. Another empty array (`array2`) is created, but it's not used in the benchmark.
2. `no empties`: Similar to the first test case, an empty array is created, but this time it's not modified.

**Comparison of Options**

The benchmark compares two approaches:

1. **Using a non-empty array**: In this approach, an empty array is created and then modified by assigning a value to its 1000th index. This is the implementation used in most JavaScript engines.
2. **Not using the array at all**: In this approach, no modifications are made to the array, effectively rendering it unused.

**Pros and Cons of Each Approach**

1. **Using a non-empty array (default behavior)**:
	* Pros: This is the typical usage scenario for `map()`, where the array is modified in some way.
	* Cons: The benchmark measures the execution time of the `map()` function, which may not accurately represent its performance when used with actual data.
2. **Not using the array at all**:
	* Pros: This approach can help mask any performance issues related to array operations or memory allocation.
	* Cons: This is an unusual usage scenario for `map()`, and the benchmark results might not be representative of real-world use cases.

**Libraries and Special JS Features**

There are no libraries mentioned in the provided benchmark code. However, it's worth noting that some JavaScript engines may have specific optimizations or features related to array operations or memory management that could affect performance.

**Special JS Feature: `item => item` Syntax**

This syntax is a shorthand for a function literal with a single expression. In this context, it simply returns the input value without modification. This syntax is widely supported in modern JavaScript engines and is often used as a placeholder or example code.

**Other Alternatives**

Some alternative approaches to measuring `map()` performance could include:

* Using a large array with random data
* Implementing a custom map function using a loop instead of recursion
* Measuring the performance of other array methods, such as `forEach()` or `reduce()`
* Comparing the performance of different JavaScript engines or versions

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.141 Safari/537.36

Browser/OS: Chrome 87 on Linux

View result in a separate tab

Test name	Executions per second
empty elements	429547.3 Ops/sec
no empties	173008.2 Ops/sec

Related benchmarks:

empty elements (version: 0)

Comparing performance of: empty elements vs no empties

Created: 3 years ago by: Guest

Jump to the latest result

empty elements

no empties

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):