Benchmark: eval vs new Function 2asdfadsfsa

Script Preparation code:

var func = new Function("return 2 * 3");
var func2 = function() { return 2 * 3 };

Tests:

eval
eval("2 * 3");
new Function
func();
func2();
func2();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
eval
new Function
func2();

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

I'd be happy to help you understand the JavaScript microbenchmark on MeasureThat.net.

**Benchmark Overview**

The benchmark compares the performance of three different approaches: `eval`, `new Function`, and a simple function declaration (`func2`). The goal is to determine which approach is fastest.

**Script Preparation Code**

The script preparation code defines two functions:

1. `var func = new Function("return 2 * 3");`: This creates a new `Function` object with the string `"return 2 * 3"` as its body.
2. `var func2 = function() { return 2 * 3 };`: This declares a simple anonymous function that returns the result of `2 * 3`.

**Test Cases**

There are three test cases:

1. `eval("2 * 3");`: This tests the performance of the built-in `eval` function.
2. `func();`: This tests the performance of the `new Function` object created in the script preparation code.
3. `func2();`: This tests the performance of the simple anonymous function declared in the script preparation code.

**Library: `Function`**

The `Function` constructor is a built-in JavaScript API that allows you to create new functions dynamically. It takes two arguments: a string containing the function body, and an optional `this` parameter (not used in this case). The purpose of this library is to enable dynamic creation of functions.

**Special JS Feature: `eval`**

The `eval` function is a built-in JavaScript API that evaluates a given string as JavaScript code. It's commonly used for parsing and executing strings containing JavaScript expressions. In this benchmark, `eval` is used to execute the string `"2 * 3"` directly.

**Performance Comparison**

The results show that:

1. `new Function` is significantly faster than `eval`, with an execution rate of approximately 10x higher.
2. The simple anonymous function (`func2`) is slower than both `new Function` and `eval`.

**Pros and Cons of Each Approach**

Here are some pros and cons of each approach:

* `eval`:
	+ Pros: Simple to use, doesn't require creating a new function object.
	+ Cons: Performance is generally slower due to its dynamic nature and potential security risks (e.g., code injection attacks).
* `new Function`:
	+ Pros: Faster performance, allows for better control over the creation process.
	+ Cons: Requires creating a new function object, which can be more complex than using `eval`.
* `func2`: (simple anonymous function)
	+ Pros: Fast execution rate, concise syntax.
	+ Cons: Requires declaring a separate variable, which may not be necessary in all cases.

**Alternatives**

If you need to create dynamic functions, you might consider alternatives like:

1. Using a library like Lodash or Underscore.js, which provide built-in `Function`-like APIs for creating functions.
2. Implementing your own function creation logic using techniques like function expressions (e.g., `var func = (function() { return 2 * 3; })();`).
3. Using a JavaScript engine that supports just-in-time compilation or Ahead-of-Time compilation, which can improve performance at the cost of complexity.

I hope this explanation helps you understand the JavaScript microbenchmark on MeasureThat.net!

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36

Browser/OS: Chrome 75 on Windows

View result in a separate tab

Test name	Executions per second
eval	2378805.8 Ops/sec
new Function	9922400.0 Ops/sec
func2();	9812506.0 Ops/sec

Related benchmarks:

eval vs new Function 2asdfadsfsa (version: 0)

Comparing performance of: eval vs new Function vs func2();

Created: 5 years ago by: Guest

Jump to the latest result

eval

new Function

func2();

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):