Benchmark: eval vs new Function strict

Script Preparation code:

var func1 = new Function('return 2 * 3');
var func2 = new Function('"use strict";return 2 * 3');

Tests:

eval
eval("2 * 3");
new Function
func1();
new Function strict
func2();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
eval
new Function
new Function strict

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Browser/OS: Chrome 117 on Windows

View result in a separate tab

Test name	Executions per second
eval	2096057.8 Ops/sec
new Function	8551078.0 Ops/sec
new Function strict	7924805.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark is comparing three different approaches:

1. `eval` (without quotes): This approach uses the built-in JavaScript function `eval()` to execute a string as code.
2. `new Function("return 2 * 3")`: This approach creates a new anonymous function using the `Function` constructor and executes it.
3. `new Function("use strict"; return 2 * 3")`: This approach creates a new anonymous function with the `"use strict"` directive and executes it.

**Options Compared**

The benchmark is comparing these three approaches in terms of their execution speed. The test cases are:

* `eval("2 * 3");`
* `func1();` (created using `new Function("return 2 * 3")`)
* `func2();` (created using `new Function("use strict"; return 2 * 3")`)

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

* **eval**: Fast, but prone to security issues due to its ability to execute arbitrary code. Can also lead to performance issues if not used carefully.
* `new Function`: Creates a new scope and is generally safer than `eval`, but can be slower due to the overhead of creating a new function object.
* `new Function("use strict"; ...)`: Similar to `new Function`, but with the added benefit of enforcing strict mode, which can improve performance and security.

**Library: Function**

The `Function` constructor is a built-in JavaScript library that allows you to create anonymous functions. It's commonly used for creating simple functions without declaring them explicitly.

**Special JS Feature/Syntax: Strict Mode**

The `"use strict"` directive is a special feature in JavaScript that enables strict mode, which improves code security and performance by enforcing certain rules and restrictions.

In this benchmark, the `new Function("use strict"; ...)` approach uses strict mode to improve performance and security.

**Other Alternatives**

If you're looking for alternatives to these approaches, here are a few options:

* **Arrow functions**: For simple cases, arrow functions (e.g., `() => 2 * 3`) can be faster than traditional function expressions.
* **Closures**: Closures (e.g., `(function() { return 2 * 3; })()`), created using the `Function` constructor or other means, can also be used as alternatives.
* **Native functions**: Depending on the use case, native functions like `Math.multiply(2, 3)` might be faster than creating a custom function.

Keep in mind that these alternatives might not provide the same level of control or flexibility as the original approaches.

Related benchmarks:

eval vs new Function strict (version: 0)

Comparing performance of: eval vs new Function vs new Function strict

Created: one year ago by: Guest

Jump to the latest result

eval

new Function

new Function strict

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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