Benchmark: Const vs Function

Tests:

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

Historical Performance Data aggregated from 24 community runs

Desktop Results:

Chrome 24 runs

const

158.7M/s

function

149.8M/s

View exact numbers

✓ const: 158,727,360 ops/sec
• function: 149,777,664 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
const
function

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36 SberBrowser/31.0.0.0

Browser/OS: Chrome 139 on Linux

View result in a separate tab

const

12.4M/s

function

11.6M/s

View exact numbers

Test name	Executions per second
✓ const	12,395,808 Ops/sec
function	11,551,119 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 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.

Const vs Function (version: 0)

Comparing performance of: `const vs function`

Created: 2 years ago by: Guest

Go to the latest result

const

function

Historical Performance Data aggregated from 24 community runs

Desktop Results:

Chrome 24 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Const vs Function (version: 0)

Comparing performance of: const vs function

Created: 2 years ago by: Guest

Go to the latest result

const

function

Historical Performance Data aggregated from 24 community runs

Desktop Results:

Chrome 24 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: `const vs function`