Benchmark: eval vs new Function

Script Preparation code:

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

Tests:

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

Historical Performance Data aggregated from 95 community runs

Desktop Results:

Chrome 55 runs

new Function

28.0M/s

eval

6.1M/s

Fastest: new Function (4.6x faster)

View exact numbers

✓ new Function: 27,965,198 ops/sec
• eval: 6,131,308 ops/sec

Firefox 16 runs

new Function

1395.3M/s

eval

3.3M/s

Fastest: new Function (421.2x faster)

View exact numbers

✓ new Function: 1,395,258,112 ops/sec
• eval: 3,312,896 ops/sec

Mobile Results:

Chrome 13 runs

new Function

7.9M/s

eval

1.9M/s

Fastest: new Function (4.1x faster)

View exact numbers

✓ new Function: 7,941,038 ops/sec
• eval: 1,937,478 ops/sec

Safari 11 runs

new Function

30.2M/s

eval

11.1M/s

Fastest: new Function (2.7x faster)

View exact numbers

✓ new Function: 30,236,308 ops/sec
• eval: 11,125,144 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

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 months ago)

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 148 on Android

View result in a separate tab

new Function

87.1M/s

eval

5.3M/s

View exact numbers

Test name	Executions per second
✓ new Function	87,123,456 Ops/sec
eval	5,308,911 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.

**Benchmark Definition**

The benchmark is comparing two approaches: using `eval()` and creating a new function with `new Function()`. The script preparation code for the first approach is:
```javascript
var func = new Function("return 2 * 3");
```
This creates a new function that takes no arguments and returns the result of evaluating "2 * 3".

**Script Preparation Code**

The script preparation code for the second approach is simply:
```javascript
eval("2 * 3");
```
This uses the built-in `eval()` function to evaluate the expression.

**What's being tested?**

The benchmark is measuring the performance difference between these two approaches. Specifically, it's testing:

* How long it takes to execute each function (in terms of CPU cycles or time)
* Which approach has a faster execution rate per second

**Options compared**

There are only two options being compared in this benchmark: `eval()` and `new Function()`. Both approaches evaluate the expression "2 * 3", but they do so in different ways.

**Pros and Cons of each approach**

* **`eval()`**:
	+ Pros:
		- Simple to use
		- Can be used for arbitrary expressions
	+ Cons:
		- Can execute arbitrary code, making it a security risk if not used carefully
		- Can be slower due to the overhead of parsing and executing the expression
* **`new Function()`**:
	+ Pros:
		- More controlled execution environment (can't execute arbitrary code)
		- May be faster due to the ability to optimize the generated function
	+ Cons:
		- Requires more code and setup compared to `eval()`

**Library used**

There is no explicit library being used in this benchmark. However, it's worth noting that some browsers may have additional optimizations or features that affect the performance of these functions.

**Special JS feature or syntax**

Neither of the approaches uses any special JavaScript features or syntax beyond basic arithmetic expressions.

**Other alternatives**

If you wanted to add more options to the benchmark, you could consider adding other ways to evaluate expressions, such as:

* Using a library like `escodegen` or `recast` to generate and optimize the expression
* Comparing the performance of different JavaScript engines (e.g., V8 vs SpiderMonkey)
* Evaluating expressions in different contexts (e.g., with and without sandboxing)

Keep in mind that adding new options would require additional benchmark preparation code, test cases, and results analysis.

I hope this explanation helps! Let me know if you have any further questions.

eval vs new Function (version: 0)

Comparing performance of: `eval vs new Function`

Created: 8 years ago by: Guest

Go to the latest result

eval

new Function

Historical Performance Data aggregated from 95 community runs

Desktop Results:

Chrome 55 runs

Firefox 16 runs

Mobile Results:

Chrome 13 runs

Safari 11 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

eval vs new Function (version: 0)

Comparing performance of: eval vs new Function

Created: 8 years ago by: Guest

Go to the latest result

eval

new Function

Historical Performance Data aggregated from 95 community runs

Desktop Results:

Chrome 55 runs

Firefox 16 runs

Mobile Results:

Chrome 13 runs

Safari 11 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `eval vs new Function`