Benchmark: Const vs Function

Tests:

const
const fun = ()=>{var a = 1}; fun();
function
function fun(){var a = 1} fun();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
const
function

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 7 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Windows

View result in a separate tab

Test name	Executions per second
const	201903456.0 Ops/sec
function	189659328.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of MeasureThat.net and explore what's being tested in this particular benchmark.

**Benchmark Definition:**

The benchmark is defined by two test cases, which compare the performance of `const` declarations versus function declarations. The script preparation code for both test cases is empty, indicating that the JavaScript engines are starting from a clean slate.

**Options Compared:**

Two options are being compared:

1. **`const` declarations**: Using the `const` keyword to declare variables that cannot be reassigned.
2. **Function declarations**: Using the `function` keyword to declare functions that can be called repeatedly.

**Pros and Cons of Each Approach:**

*   **`const` Declarations:**
    *   Pros:
        *   Faster lookups, as the compiler can optimize for constant expressions.
        *   Memory safety, as variables cannot be reassigned accidentally.
    *   Cons:
        *   May not support dynamic changes to variable values.
        *   Can lead to confusing code if used incorrectly (e.g., assigning a new value to a `const` variable).
*   **Function Declarations:**
    *   Pros:
        *   Allows for dynamic function behavior and flexibility in coding.
        *   Supports method overriding and inheritance through prototypal inheritance.
    *   Cons:
        *   May lead to slower performance due to the overhead of creating and managing functions.

**Library and Special JS Features:**

There are no libraries mentioned in the benchmark definition. However, it's worth noting that JavaScript engines may use various internal optimizations or features, such as:

*   **Arrow Functions**: Introduced in ECMAScript 2015 (ES6), arrow functions provide a concise syntax for defining small, one-time-use functions.
*   **Function Expressions**: Used to create anonymous functions, which can be useful for event handling and other scenarios.

**Other Considerations:**

When writing benchmarks like this one, consider the following factors:

*   **Language Features:** Focus on language features that are commonly used in real-world applications. Avoid benchmarking esoteric or niche features.
*   **Compiler Optimizations:** Ensure that the script preparation code accurately represents typical use cases and compiler optimizations.
*   **Benchmark Size and Complexity:** Keep benchmarks concise and manageable to avoid overwhelming users with excessive data.

**Alternative Benchmarks:**

Some alternative benchmark ideas could explore:

*   **Null vs. Undefined**: Compare the performance of accessing `null` versus `undefined` variables in JavaScript engines.
*   **For Loops vs. Array.prototype.forEach()**: Measure the speed of traditional for loops versus using `Array.prototype.forEach()` to iterate over arrays.
*   **Template Literals vs. String Concatenation**: Benchmark the performance of template literals versus concatenating strings using the `+` operator.

These benchmarks would provide valuable insights into various JavaScript performance topics and help developers optimize their code for better execution times.

Related benchmarks:

Const vs Function (version: 0)

Comparing performance of: const vs function

Created: one year ago by: Guest

Jump to the latest result

const

function

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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