Benchmark: window.eval function vs new Function1

Tests:

eval
var func = window.eval("function fn() { return 2 * 3 }"); func();
new Function
var func = new Function("return 2 * 3"); 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:

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

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 131 on Android

View result in a separate tab

Test name	Executions per second
eval	0.0 Ops/sec
new Function	627730.2 Ops/sec

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.

**What is being tested?**

The benchmark is comparing two approaches to create an anonymous function in JavaScript: `window.eval` and `new Function`. The goal is to determine which approach is faster, as measured by the number of executions per second.

**Options compared**

Two options are being compared:

1. **`window.eval`**: This method creates a new function by executing a string as JavaScript code. It's often used for client-side scripting and is available in all modern browsers.
2. **`new Function`**: This method creates a new function by passing a string of JavaScript code to the `Function` constructor. It's also widely supported in modern browsers.

**Pros and Cons**

Here are some pros and cons of each approach:

*   **`window.eval`**:
    *   Pros:
        *   Generally faster than `new Function`, as it avoids the overhead of creating a new function object.
        *   Simplifies code, as you don't need to worry about function syntax or quotes.
    *   Cons:
        *   Can be security risk if used with untrusted input, as it can execute arbitrary JavaScript code.
        *   May not work in all environments (e.g., older browsers, Node.js).
*   **`new Function`**:
    *   Pros:
        *   Provides better control over the function's syntax and behavior.
        *   Can be used with untrusted input, making it more secure than `window.eval`.
    *   Cons:
        *   Generally slower than `window.eval`, due to the overhead of creating a new function object.

**Library/dependency usage**

There is no library or dependency being used in this benchmark. The code is pure JavaScript.

**Special JS features/syntax**

There are no special JavaScript features or syntax being used in this benchmark. It's focused on comparing two basic approaches to create an anonymous function.

**Alternative approaches**

If you wanted to test other approaches, some alternatives could include:

*   **`Function.prototype`**: This method creates a new function by passing a string of JavaScript code to the `Function.prototype` constructor.
*   **`eval` with a `with` clause**: This approach uses `eval` with a `with` clause to create an anonymous function. However, this is generally slower and less secure than `window.eval`.

To test these alternatives, you would need to modify the benchmark's code and update the `Benchmark Definition` json accordingly.

Here is how the updated Benchmark Definition might look like:

```json
{
    "Name": "eval vs new Function",
    "Description": null,
    "Script Preparation Code": null,
    "Html Preparation Code": null
}
```

And here is an example of a test case for `Function.prototype` and alternative approach using `eval` with a `with` clause:

```json
{
    "Benchmark Definition": "var func = new Function(\"return 2 * 3\");\r\nfunc();",
    "Test Name": "new Function"
},
{
    "Benchmark Definition": "with ({})) { var func = eval(\"function fn() { return 2 * 3 }\"); func(); }",
    "Test Name": "eval with with clause"
}
```

You can add more test cases to compare other approaches, depending on your specific needs and goals.

Related benchmarks:

window.eval function vs new Function1 (version: 0)

Comparing performance of: eval vs new Function

Created: 4 years ago by: Guest

Jump to the latest result

eval

new Function

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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