Benchmark: function object vs function

Script Preparation code:

function func() {
  const n = 100000;
  let result = 0;
  for (let i = 0; i < n; i++) {
    result += i;
  }
  return result;
}

var func2 = new Function(`
  const n = 100000;
  let result = 0;
  for (let i = 0; i < n; i++) {
    result += i;
  }
  return result;
`);

Tests:

function
func()
function object
func2()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
function
function object

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/605.1.15 (KHTML, like Gecko) Version/17.2.1 Safari/605.1.15

Browser/OS: Safari 17 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
function	14135.7 Ops/sec
function object	11709.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Overview**

The provided benchmark measures the performance difference between two approaches: creating a function using the `function` keyword and creating a function using the `new Function()` constructor.

**Options Compared**

There are two options being compared:

1. **Function Creation using `function`**: This approach creates a function by declaring a function block with the `function` keyword. The function body is defined inside the function declaration.
2. **Function Creation using `new Function()`**: This approach creates a function by using the `new Function()` constructor, which takes a string containing the function's code as an argument.

**Pros and Cons**

**1. Function Creation using `function`:**

Pros:

* Easier to read and understand for developers familiar with traditional function declaration syntax.
* No need to escape special characters in the function body.

Cons:

* May not be optimized by the JavaScript engine, leading to slower execution times compared to the `new Function()` approach.

**2. Function Creation using `new Function():`

Pros:

* Can take advantage of optimizations provided by the JavaScript engine, potentially resulting in faster execution times.
* Allows for more flexibility in defining complex function bodies without worrying about escaping special characters.

Cons:

* Less readable and maintainable due to its syntactic sugar nature.
* Requires careful consideration when writing the function's string argument to avoid security vulnerabilities (e.g., injecting malicious code).

**Library: `Function`**

The `Function` constructor is a built-in JavaScript object that allows creating new functions from string literals. Its purpose is to provide a way to dynamically create functions without having to declare them using traditional syntax.

In the provided benchmark, `func2` is created using the `new Function()` constructor to define its body, which mirrors the code of the `func()` function declared directly with the `function` keyword.

**Special JS Feature: Syntax Sugar**

The use of `new Function()` in this benchmark leverages a syntax sugar feature introduced in ECMAScript 5 (ES5). The `Function` constructor provides a convenient way to create functions, but it's worth noting that some modern JavaScript engines may optimize the creation and execution of these functions differently.

**Other Alternatives**

If you're interested in exploring other approaches for measuring performance in JavaScript, consider the following:

* **Native Function Creation**: Creating functions using traditional syntax (`function` keyword) is a well-established approach.
* **Closures**: Closures are another way to create functions without using the `new Function()` constructor. They involve creating an inner function that has access to its surrounding scope.
* **Proxy Functions**: Proxy functions are used in some JavaScript engines (like SpiderMonkey) for better performance and flexibility.

For measuring performance, it's also essential to consider factors beyond just the approach used for function creation:

* **Optimization Strategies**: Minification, compression, and caching can significantly impact the results.
* **Platform Considerations**: Different platforms, browsers, and environments may exhibit varying behavior due to their respective implementation details (e.g., WebAssembly).
* **Testing Frameworks**: Using a well-structured testing framework can help ensure accurate and reliable performance measurements.

Keep in mind that JavaScript's performance landscape is constantly evolving. Always consider the context of your specific use case and test environment when choosing benchmarks or optimization strategies.

Related benchmarks:

function object vs function (version: 0)

Comparing performance of: function vs function object

Created: one year ago by: Registered User

Jump to the latest result

function

function object

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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