Benchmark: normal vs eval - MeasureThat.net

Tests:

normal code
(() => { let a = 1; return () => console.log(a); })()();
eval code
(() => { let a = 1; return () => eval('console.log(a)'); })()();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
normal code
eval code

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/113.0.0.0 Safari/537.36

Browser/OS: Chrome 113 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
normal code	455086.7 Ops/sec
eval code	363977.9 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Definition JSON**

The provided Benchmark Definition JSON defines two test cases:

* `normal vs eval`: This benchmark compares the performance of two approaches:
	+ `normal code`: Using normal JavaScript syntax to execute a function that returns another function, which logs the value of a variable to the console.
	+ `eval code`: Using the `eval` function to evaluate a string containing the expression `console.log(a)`, where `a` is a variable with the value 1.

**Options Compared**

The two approaches differ in how they execute the inner function. The main difference lies in whether the inner function is executed directly or through the use of `eval`.

* **Normal code**: In this approach, the inner function is defined and then executed immediately using the parentheses `()`. This means that the variable `a` is declared and assigned a value before it's used.
* **Eval code**: Here, the string `"console.log(a)"` is passed to the `eval` function. The `eval` function executes the provided expression as JavaScript code at runtime, which means that the variable `a` is looked up in the global scope (or local scope, depending on how it's accessed) before its value is used.

**Pros and Cons**

Both approaches have their advantages and disadvantages:

* **Normal code**:
	+ Pros: More predictable behavior, easier to understand, and less prone to errors.
	+ Cons: May be slower due to the overhead of function declaration and execution.
* **Eval code**:
	+ Pros: Can lead to faster execution times in some cases, as it bypasses function creation and parameter checking.
	+ Cons: More error-prone, as the `eval` function can execute arbitrary JavaScript code, potentially introducing security vulnerabilities.

**Library Usage**

There is no library usage mentioned in the provided Benchmark Definition JSON. However, if a library was used, it would likely be something like `console` or a logging library, which are common dependencies for benchmarking and testing purposes.

**Special JS Feature/Syntax**

The `eval` function is a special JavaScript feature that allows evaluating expressions as JavaScript code at runtime. This syntax is generally discouraged in production code due to potential security risks but can be useful in certain cases, such as parsing user-inputted data or loading dynamic content.

Overall, the choice between `normal vs eval` depends on the specific use case and performance requirements. If predictability and reliability are crucial, normal code might be a better choice. However, if speed is more important, `eval code` could provide better results, albeit at the cost of increased error risk.

**Other Alternatives**

For measuring JavaScript performance, there are other benchmarking tools and libraries available, such as:

1. **Benchmark.js**: A popular JavaScript library for running benchmarks.
2. **Jest**: A testing framework that includes built-in support for running benchmarks.
3. **BenchmarkRunner**: A tool for running custom benchmarks in Node.js.

These alternatives offer varying levels of flexibility, performance, and ease of use, depending on the specific needs of your project.

Related benchmarks:

normal vs eval (version: 0)

Comparing performance of: normal code vs eval code

Created: 2 years ago by: Guest

Jump to the latest result

normal code

eval code

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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