Benchmark: eval'd function vs. new Function

Script Preparation code:

var func1 = new Function("a", "b", "return a * b");
var func2 = eval("(function (a, b) { return a * b; })");

Tests:

eval
func1(2, 3);
new Function
func2(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 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36

Browser/OS: Chrome 103 on Windows

View result in a separate tab

Test name	Executions per second
eval	17507192.0 Ops/sec
new Function	17524996.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark and explain what's being tested, the pros and cons of each approach, and other considerations.

**Benchmark Overview**

The benchmark compares two ways to create and execute a simple mathematical function: `eval` and `new Function`. The test cases are designed to measure which method is faster and more efficient.

**Script Preparation Code**

In this code, we have:

```javascript
var func1 = new Function("a", "b", "return a * b");
var func2 = eval("(function (a, b) { return a * b; })");
```

Here's what's happening:

* `new Function` creates a new function object with the specified parameters and body. In this case, it takes two arguments `a` and `b`, and returns their product.
* `eval` is used to evaluate the provided string as JavaScript code. The string defines an anonymous function that takes two arguments `a` and `b` and returns their product.

**Test Cases**

The benchmark has two test cases:

1. **`eval`**: This test case calls the `eval` function with the string `(function (a, b) { return a * b; })`. The goal is to measure how fast this code executes.
2. **`new Function`**: This test case creates a new function object using the `new Function` syntax and then calls it with the arguments `2` and `3`.

**Library and Features**

* `eval` uses the built-in JavaScript `eval` function, which is an implementation of the Turing complete Scheme dialect. The use of `eval` can be considered as a security risk if not used carefully, as it can evaluate arbitrary JavaScript code.
* No special JS features or syntax are used in this benchmark.

**Pros and Cons**

* **`new Function`**:
	+ Pros: This approach creates a new function object that is optimized for execution. It avoids the overhead of `eval`.
	+ Cons: Creating a new function object requires more memory allocation than using `eval`.
* **`eval`**:
	+ Pros: Using `eval` allows for more flexibility and can be faster in some cases, as it doesn't require creating a new function object.
	+ Cons: As mentioned earlier, using `eval` can pose security risks if not used carefully.

**Benchmark Results**

The latest benchmark results show that the `new Function` approach is slightly faster than `eval`. However, this may depend on various factors such as the specific JavaScript engine, hardware, and other code in the benchmark.

**Other Alternatives**

If you're looking for alternatives to these approaches:

* Instead of using `eval`, you can use a library like `parse` or `Function` from `es5-shim` to parse and execute the provided string.
* If performance is critical, you can use native code compilation tools like Emscripten or V8's `toNativeCode()` function to generate optimized machine code.

Keep in mind that these alternatives may come with their own trade-offs and requirements.

Related benchmarks:

eval'd function vs. new Function (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 2 months ago):