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

Script Preparation code:

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

Tests:

eval
eval("let r = 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: 7 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:142.0) Gecko/20100101 Firefox/142.0

Browser/OS: Firefox 142 on Linux

View result in a separate tab

Test name	Executions per second
eval	1452304.4 Ops/sec
new Function	4180162.0 Ops/sec
regular	4197604.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks and explore what's being tested on MeasureThat.net.

**Benchmark Overview**

The benchmark consists of three test cases: `eval`, `new Function`, and `regular`. The goal is to compare their performance in executing a specific JavaScript function. We'll break down each test case, explain what's happening under the hood, and discuss pros and cons.

**Test Case 1: eval**

`eval` is a built-in JavaScript function that executes a string as if it were code. In this test case, the string `"let r = Math.random().toString(36).substring(7).includes('x');;"` defines a variable `r` using a random value generated by `Math.random()`. The `eval` function then evaluates and returns the result of that expression.

**Pros:**

* Simple to implement
* Fast execution (since it's just interpreting code)

**Cons:**

* Potential security risks, as `eval` can execute arbitrary code
* May be slower due to the overhead of parsing and executing the string

**Test Case 2: new Function**

In this test case, a new function is created using the `new Function` syntax. The same string `"let r = Math.random().toString(36).substring(7).includes('x');;"` defines a variable `r`, just like in the `eval` test case.

**Pros:**

* Similar to `eval`, but with better security guarantees
* May be faster due to the compiler optimization of the generated code

**Cons:**

* Still involves function creation, which can incur overhead
* Not as simple to implement as `eval`

**Test Case 3: regular**

This test case uses a named function expression instead of `new Function` or `eval`. The same string `"let r = Math.random().toString(36).substring(7).includes('x');;"` defines a variable `r`, just like in the other two test cases.

**Pros:**

* Similar to `eval` and `new Function`
* May be faster due to the compiler optimization of the generated code

**Library/Function Usage**

None of these test cases use any external libraries or functions. The focus is on comparing the performance of different JavaScript features.

**Special JS Features/Syntax**

There are no special JavaScript features or syntax used in this benchmark. It's a straightforward comparison of three simple execution methods.

**Alternative Approaches**

Other approaches to executing code could include:

* `String.prototype.execute()` (if supported by the browser)
* `Function()`, without using `new`
* Compiler-based optimizations, such as ES6 modules or WebAssembly
* Native code generation and execution (e.g., using WebAssembly)

Keep in mind that these alternatives might not be supported by all browsers or environments. MeasureThat.net's focus is on comparing JavaScript features, so it uses a more controlled and standardized approach.

I hope this explanation helps you understand what's happening in the MeasureThat.net benchmark!

Related benchmarks:

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

Comparing performance of: eval vs new Function vs regular

Created: 5 years 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):