Benchmark: eval vs new Function vs function(Sample JS Functions)2

Script Preparation code:

var newFunc = new Function("return Math.random().toString(36).substring(7).includes('x');");
var regular = function(){
return Math.random().toString(36).substring(7).includes('x');;
}

Tests:

eval
eval("Math.random().toString(36).substring(7).includes('x');");
new Function
newFunc();
regular
regular()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
eval
new Function
regular

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36 Edg/124.0.0.0

Browser/OS: Chrome 124 on Windows

View result in a separate tab

Test name	Executions per second
eval	2427326.0 Ops/sec
new Function	4986992.5 Ops/sec
regular	3444326.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided JSON represents a JavaScript microbenchmark test case on MeasureThat.net. The benchmark compares three different approaches to execute a simple JavaScript function: `eval`, `new Function`, and a regular function.

**Script Preparation Code Explanation**

The script preparation code is used to define two sample JavaScript functions:

1. `var newFunc = new Function("return Math.random().toString(36).substring(7).includes('x');");` This line defines a new function using the `Function` constructor, which takes an anonymous function as its argument.
2. `var regular = function(){ return Math.random().toString(36).substring(7).includes('x');};` This line defines a regular function using the `function` keyword.

The purpose of these functions is to test the performance of different approaches to execute a simple JavaScript function that includes a random string and checks if it contains the character 'x'.

**Options Compared**

The benchmark compares three options:

1. **eval**: The `eval` function executes the code passed as a string.
2. **new Function**: As mentioned earlier, this approach uses the `Function` constructor to execute an anonymous function.
3. **regular (function)**: This approach uses a regular function defined using the `function` keyword.

**Pros and Cons of Each Approach**

1. **eval**:
	* Pros: Fast execution and low overhead.
	* Cons: Can be vulnerable to security threats if used with untrusted input, and can execute arbitrary code due to its ability to execute strings as JavaScript code.
2. **new Function**:
	* Pros: Provides better protection against security threats compared to `eval`, and can execute anonymous functions securely.
	* Cons: May have higher overhead compared to `eval` due to the creation of a new function object.
3. **regular (function)**:
	* Pros: Provides good performance and is relatively secure, as it executes JavaScript code within a defined scope.
	* Cons: May not be suitable for all use cases where dynamic function execution is required.

**Other Considerations**

* **Library Usage**: None of the tested approaches rely on any external libraries.
* **Special JS Features/Syntax**: The benchmark does not use any special JavaScript features or syntax, such as async/await, promises, or modern JavaScript language features.

**Alternatives to These Approaches**

If you need to execute dynamic code in your application, consider using:

1. **Function constructors (e.g., `new Function()`) for secure execution of anonymous functions.
2. **eval with strict mode** for a balance between security and performance.
3. **Regular function definitions** for predictable and secure execution.

Keep in mind that each approach has its trade-offs and should be chosen based on the specific requirements and constraints of your application.

Related benchmarks:

eval vs new Function vs function(Sample JS Functions)2 (version: 0)

Comparing performance of: eval vs new Function vs regular

Created: one year ago by: Guest

Jump to the latest result

eval

new Function

regular

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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