Benchmark: eval vs Function with function creation at runtime

Tests:

eval
eval("2 * 3")
new Function
Function("return 2 * 3")()

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:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.4 Safari/605.1.15

Browser/OS: Safari 15 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
eval	8119868.5 Ops/sec
new Function	279327.6 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**What is being tested?**

The benchmark compares two approaches to evaluating and executing JavaScript code:

1. `eval()`: A built-in JavaScript function that parses the string as JavaScript code and executes it.
2. Creating a new `Function` object with a runtime-constructed string using the syntax `new Function("expression")()`.

**Options compared:**

The benchmark is comparing the performance of these two approaches in executing simple arithmetic expressions (e.g., `2 * 3`).

**Pros and Cons:**

1. **eval()**:
	* Pros:
		+ Simple to use, as it requires only a string.
		+ Fast execution, since it's a built-in function.
	* Cons:
		+ Can be vulnerable to security issues (e.g., code injection) if not used carefully.
		+ May have performance issues due to the parsing and execution overhead.
2. **new Function()**:
	* Pros:
		+ More secure, as it doesn't execute arbitrary code directly.
		+ Can provide better performance control, since the expression is parsed only once.
	* Cons:
		+ Requires more code to use (constructing a `Function` object).
		+ May have slower execution due to the parsing and evaluation overhead.

**Other considerations:**

Both approaches can be affected by factors like JavaScript engine optimizations, caching, and input data. The benchmark results may also depend on the specific JavaScript engine implementation used in each browser.

**Library or feature used:**

None are explicitly mentioned in this benchmark definition.

**Special JS features or syntax:**

The `eval()` function uses a special syntax, as it allows executing arbitrary JavaScript code from a string. However, since the benchmark is comparing two simple arithmetic expressions, no other specialized syntax is relevant here.

Now, let's look at some alternatives:

Alternatives to `eval()` could be:

* Using `Function` constructors with runtime-constructed strings (similar to the second test case in this benchmark).
* Employing libraries like `esprima` or `recast` for parsing and executing JavaScript code.
* Using alternative evaluation methods, such as using `JSON.parse()` and `eval()` separately or employing a custom parser.

Alternatives to creating a new `Function` object could be:

* Using `Bind()` or `Apply()` to execute functions with dynamic arguments.
* Employing libraries like `lodash.function` for functional programming.
* Utilizing more advanced JavaScript features, such as arrow functions or `this` binding.

Keep in mind that these alternatives may have different performance characteristics, security implications, or use cases compared to the approaches used in this benchmark.

Related benchmarks:

eval vs Function with function creation at runtime (version: 0)

Comparing performance of: eval vs new Function

Created: 2 years ago by: Guest

Jump to the latest result

eval

new Function

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):