Benchmark: eval vs new Function v2

Script Preparation code:

var func = new Function("return 2 * 3");

Tests:

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

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.

I'd be happy to explain the benchmark and its results.

**Benchmark Definition**

The provided JSON represents a JavaScript microbenchmark that compares two approaches: `new Function` and `eval`. The benchmark is defined by two scripts:

1. "Script Preparation Code": This code defines a function `func` using the `new Function` constructor, which takes a string argument `"return 2 * 3;"` as its body. When executed, this function will return the result of evaluating the expression `2 * 3`.
2. The first individual test case: "Benchmark Definition": This is a simple `eval` statement that evaluates the expression `2 * 3`.

The benchmark aims to measure which approach is faster.

**Options Compared**

Two approaches are compared:

1. **new Function**: Using the `new Function` constructor to create a new function, and then executing it.
2. **eval**: Directly using the `eval` function to evaluate an expression.

**Pros and Cons of Each Approach**

* **new Function**:
	+ Pros: More secure and efficient than `eval`, as it doesn't execute arbitrary code.
	+ Cons: Requires creating a new function object, which can have overhead due to memory allocation and creation of the function's environment.
* **eval**:
	+ Pros: Very fast, as it can directly evaluate an expression without creating any intermediate objects or functions.
	+ Cons: Insecure, as it can execute arbitrary code if the input is not sanitized.

**Library and Purpose**

In this benchmark, there is no explicit library used. However, `new Function` uses a constructor function internally to create the function object, which is a part of the JavaScript language specification.

**Special JS Feature or Syntax**

There are no special features or syntaxes mentioned in this benchmark.

**Other Considerations**

When evaluating the performance of these two approaches, it's essential to consider the following factors:

* Security: In real-world applications, using `eval` can be a significant security risk if not properly sanitized. In contrast, `new Function` is generally more secure.
* Performance: As mentioned earlier, both approaches have different overheads due to memory allocation and execution.

**Alternatives**

If you were to compare these two approaches in a real-world scenario, you might also consider other alternatives:

1. **Function expressions**: Instead of using the `new Function` constructor, you could use an anonymous function expression (e.g., `(function() { return 2 * 3; })()`).
2. **Arrow functions**: If available, arrow functions can be a more concise and efficient way to define small functions.
3. **Closures**: You could also explore using closures, where the result of one function is used as an argument to another function.

Keep in mind that these alternatives may have different trade-offs regarding security, performance, and readability, depending on your specific use case.

Related benchmarks:

eval vs new Function v2 (version: 0)

Comparing performance of: eval vs new Function

Created: 6 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):