Benchmark: Switch vs lookup

Script Preparation code:

var pageNumber = 'test';
var pageRouteName;
var lookup = {
    One: 'create-very-one',
    Two: 'create-very-two',
    Three: 'create-very-three',
    Four: 'create-very-four',
    Five: 'create-very-five',
    Six: 'create-very-six',
    Seven: 'create-very-seven',
    Eight: 'create-very-eight',
    Nine: 'create-very-nine'
}

Tests:

Switch
switch (pageNumber) { case 'One': pageRouteName = 'create-very-one'; break; case 'Two': pageRouteName = 'create-very-two'; break; case 'Three': pageRouteName = 'create-very-three'; break; case 'Four': pageRouteName = 'create-very-four'; break; case 'Five': pageRouteName = 'create-very-five'; break; case 'Six': pageRouteName = 'create-very-six'; break; case 'Seven': pageRouteName = 'create-very-seven'; break; case 'Eight': pageRouteName = 'create-very-eight'; break; case 'Nine': pageRouteName = 'create-very-nine'; break; default: { throw new Error(`Page of given number is not allowed. Given page number: ${pageNumber}.`); } }
Object lookup
pageRouteName = lookup[pageNumber];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Switch
Object lookup

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.0

Browser/OS: Firefox 140 on Linux

View result in a separate tab

Test name	Executions per second
Switch	0.0 Ops/sec
Object lookup	596026368.0 Ops/sec

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

LLMs can make mistakes. Check important info.

This benchmark compares the performance of two methods for determining a string value based on a given input:  a `switch` statement and an object lookup using a property name.

Let's break down each option:

**1. `Switch` Statement:** This is a traditional control flow structure in JavaScript that evaluates an expression (in this case, the `pageNumber`) against several possible cases. If a match is found, the corresponding code block is executed.

* **Pros:** Can be very readable and concise for simple scenarios like this.
   * **Cons:** Performance can suffer if there are many cases, as it involves comparing the input to each case sequentially.

**2. Object Lookup:** This method uses an object (`lookup`) where keys represent possible `pageNumber` values and values are the corresponding strings. The code directly accesses the value associated with the given `pageNumber`.

* **Pros:** Generally faster than a `switch` statement, especially for a large number of cases, because it involves direct access to the desired property (which can be an efficient lookup in modern JavaScript engines).
   * **Cons:** Can be slightly less readable if there are many entries in the object.

**Considerations:**

* **Number of Cases:** The `switch` statement might perform better for a small number of cases, while the object lookup shines when dealing with many cases.
* **Maintainability:** The object lookup approach can sometimes be more maintainable as adding or removing cases involves simply modifying the object.

**Alternatives:**

* **Maps (ES6):**  Similar to objects but provide faster key lookups due to their internal implementation (hash tables).

In this specific benchmark, the `Object lookup` method clearly outperforms the `switch` statement. This aligns with general expectations about performance differences between these approaches.

Related benchmarks:

Switch vs lookup (version: 0)

Comparing performance of: Switch vs Object lookup

Created: 6 years ago by: Guest

Jump to the latest result

Switch

Object lookup

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):