Benchmark: eval vs new Functionx

Script Preparation code:

var f = 'a => a + 1'

Tests:

eval
eval(f);
new Function
new Function('return ' + f)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
eval
new Function

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and the pros/cons of different approaches.

**What is being tested?**

The benchmark measures the performance difference between two ways to create an anonymous function: using `eval` and creating a new `Function` object using the `new Function()` constructor.

**Options being compared:**

1. **eval**: The `eval()` function executes a string as JavaScript code, allowing dynamic evaluation of expressions.
2. **new Function()**: This constructor creates a new function object from a given string or expression.

**Pros and Cons:**

* **eval()**:
	+ Pros:
		- Allows for dynamic evaluation of expressions.
		- Can be useful in certain scenarios where the code to execute is not known beforehand.
	+ Cons:
		- Performance overhead due to the need to parse and execute the string as JavaScript code.
		- Security risks if the input string is not properly sanitized, as it can lead to arbitrary code execution.
* **new Function()**:
	+ Pros:
		- More efficient than `eval()` since it avoids parsing and executing the string as code.
		- Safer than `eval()` since it does not execute arbitrary code without validation.
	+ Cons:
		- Requires the input expression to be a valid JavaScript function string, which can limit its flexibility.

**Library/Feature usage:**

There is no specific library being used in this benchmark. However, the use of anonymous functions (`a => a + 1`) relies on the syntax introduced in ECMAScript 2015 (ES6), also known as "arrow functions." This feature allows for concise and expressive function definitions.

**Other considerations:**

* The benchmark focuses solely on the performance difference between `eval()` and `new Function()`, excluding other factors like memory usage, code readability, or maintainability.
* The test cases use a simple expression (`a => a + 1`) to demonstrate the performance difference between the two approaches. In real-world scenarios, more complex expressions may have different performance characteristics.

**Alternative approaches:**

Other ways to create anonymous functions include:

* Using the `Function` constructor without the `new` keyword (e.g., `var f = new Function('return ' + x)`).
* Using a callback function with an immediately invoked function expression (IIFE), like this: `(a) => { return a + 1; }`.
* Utilizing other functional programming features, such as map-reduce or arrow functions in older browsers.

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

Related benchmarks:

eval vs new Functionx (version: 0)

Comparing performance of: eval vs new Function

Created: 7 years ago by: Guest

Jump to the latest result

eval

new Function

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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