Benchmark: Switch vs lookup3

Script Preparation code:

var pageNumber = 'Five';
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:

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided benchmark compares the performance of two approaches: Switch statement and Object lookup.

**Switch Statement**

The first test case uses a Switch statement to determine the value of `pageRouteName` based on the value of `pageNumber`. The Switch statement is compared to an alternative approach that uses Object lookup.

**Object Lookup**

The second test case uses an object literal (`lookup`) to map values of `pageNumber` to corresponding strings. This approach is compared to the traditional Switch statement.

**Pros and Cons**

Here are some pros and cons of each approach:

* **Switch Statement**
	+ Pros:
		- Easy to read and maintain, especially for small numbers of cases.
		- Can be optimized by compiler or runtime environment (e.g., inlining, folding) if necessary.
	+ Cons:
		- Can lead to slower execution times due to the overhead of branch prediction and misprediction penalties.
		- May not be as flexible as Object lookup for large numbers of cases or dynamic values.
* **Object Lookup**
	+ Pros:
		- Fast and efficient, especially with modern JavaScript engines that optimize array lookups (e.g., `Array.prototype.indexOf`).
		- Can handle large numbers of cases without significant performance degradation.
	+ Cons:
		- May be less readable or maintainable for developers unfamiliar with Object lookup patterns.
		- Requires a separate object definition, which can add overhead in certain scenarios.

**Library and Special JS Feature**

Neither test case uses any external libraries. However, it's worth noting that the `lookup` object is defined as a local variable within the script preparation code.

**Other Considerations**

When choosing between these two approaches, consider the following factors:

1. **Readability**: If maintainability and readability are crucial for your project, Switch statement might be a better choice.
2. **Performance**: If performance is critical, Object lookup might offer slightly faster execution times due to its optimized array lookups.
3. **Scalability**: For large numbers of cases or dynamic values, Object lookup can provide more flexibility without sacrificing performance.

**Alternatives**

Other alternatives for similar use cases include:

* Using `Array.prototype.indexOf` or `Array.prototype.includes` with an object literal
* Employing other data structures like maps or sets for fast lookups
* Leveraging modern JavaScript features like `switch` expressions (introduced in ECMAScript 2017) for more concise and readable code

Keep in mind that the choice of approach ultimately depends on your specific use case, performance requirements, and personal preference.

Related benchmarks:

Switch vs lookup3 (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

No previous run results

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