Benchmark: switch vs if vs object selector

Script Preparation code:

function getRandomInt(max) {
  return Math.floor(Math.random() * Math.floor(max));
}

Tests:

Switch
let x= ""; const i = getRandomInt(6); switch(i) { case 0: x= "Zero"; break; case 1: x= "One"; break; case 2: x= "Two"; break; case 3: x= "Three"; break; case 4: x= "Four"; break; case 5: x= "Five"; break; }
If (else)
let x = ""; const i = getRandomInt(6); if (i === 0) x = "Zero" else if (i === 1) x = "One" else if (i === 2) x = "Two" else if (i === 3) x = "Three" else if (i === 4) x = "Four" else if (i === 5) x = "Five"
Object selector
let x = ""; const i = getRandomInt(6); x = { 0: "Zero", 1: "One", 2: "Two", 3: "Three", 4: "Four", 5: "Five", }[i];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Switch
If (else)
Object selector

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**Benchmark Definition**

The benchmark is designed to compare the performance of three different approaches: `switch` statement, `if-else` statement, and object selector (also known as a hash table lookup).

**Options Compared**

1. **Switch Statement**: A `switch` statement uses a value to determine which code block to execute. In this case, it's used to assign a string value to variable `x` based on the random integer `i`.
2. **If-Else Statement**: An `if-else` statement checks if a condition is true and executes one branch if true and another branch if false. Here, it's used in an equivalent way to the `switch` statement.
3. **Object Selector (Hash Table Lookup)**: This approach uses an object with key-value pairs to look up the string value for variable `x` based on the random integer `i`.

**Pros and Cons of Each Approach**

1. **Switch Statement**: Pros:
	* Compact code
	* Easy to read and understand
	* Optimized by the JavaScript engine for cases where the number of possible values is small (like in this benchmark)
Cons:
	* Limited to a fixed number of cases
	* Can be slower if the number of cases increases significantly
2. **If-Else Statement**: Pros:
	* Flexible and can handle any number of cases
	* Easy to add or remove cases as needed
Cons:
	* More verbose code compared to `switch`
	* May incur performance overhead due to branch prediction issues
3. **Object Selector (Hash Table Lookup)**: Pros:
	* Fast lookups for large numbers of keys
	* Easy to add or remove keys as needed
Cons:
	* Requires additional memory allocation and management
	* May be slower than `switch` if the number of possible values is small

**Library and Special JS Feature**

There doesn't appear to be any specific library used in this benchmark. However, it's worth noting that modern JavaScript engines have various optimizations and features that can affect performance, such as:

* **JIT (Just-In-Time) compilation**: some JavaScript engines compile code into machine code on the fly, which can improve performance.
* **Cache optimization**: some JavaScript engines use caching to store frequently accessed data, which can reduce memory allocation and deallocation overhead.

**Other Alternatives**

If you're looking for alternative approaches or want to explore more performance-optimized options, consider:

1. **Using a lookup table**: Create a precomputed array of values for each possible `i` value and use it directly.
2. **Memoization**: Store the results of previous evaluations of the expression and reuse them instead of recalculating them.
3. **Parallel processing**: Divide the work among multiple threads or processes to take advantage of multi-core processors.

Keep in mind that these alternatives may introduce additional complexity, require more memory, or have different performance characteristics compared to the original `switch`, `if-else`, and object selector approaches.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36

Browser/OS: Chrome 96 on Linux

View result in a separate tab

Test name	Executions per second
Switch	1255065.9 Ops/sec
If (else)	1271773.8 Ops/sec
Object selector	1280706.1 Ops/sec

Related benchmarks:

switch vs if vs object selector (version: 3)

Comparing performance of: Switch vs If (else) vs Object selector

Created: 4 years ago by: Registered User

Jump to the latest result

Switch

If (else)

Object selector

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):