Benchmark: if-else vs switch case

Tests:

Switch case
const a = 1; switch (a) { case 5: console.log("a is 5"); break; case 4: console.log("a is 4"); break; case 3: console.log("a is 4"); break; case 41: console.log("a is 4"); break; case 31: console.log("a is 4"); break; case 42: console.log("a is 4"); break; case 33: console.log("a is 4"); break; case 44: console.log("a is 4"); break; case 35: console.log("a is 4"); break; case 46: console.log("a is 4"); break; case 37: console.log("a is 4"); break; case 48: console.log("a is 4"); break; case 39: console.log("a is 4"); break; case 40: console.log("a is 4"); break; case 311: console.log("a is 4"); break; case 422: console.log("a is 4"); break; case 333: console.log("a is 4"); break; case 444: console.log("a is 4"); break; case 355: console.log("a is 4"); break; case 2: console.log("a is 2"); break; case 1: console.log("a is 1"); break; }
if-else
const a = 1; if (a === 5) { console.log("a is 5"); } else if (a === 4) { console.log("a is 4"); } else if (a === 3) { console.log("a is 4"); } else if (a === 41) { console.log("a is 4"); } else if (a === 31) { console.log("a is 4"); } else if (a === 42) { console.log("a is 4"); } else if (a === 33) { console.log("a is 4"); } else if (a === 44) { console.log("a is 4"); } else if (a === 35) { console.log("a is 4"); } else if (a === 46) { console.log("a is 4"); } else if (a === 37) { console.log("a is 4"); } else if (a === 48) { console.log("a is 4"); } else if (a === 39) { console.log("a is 4"); } else if (a === 40) { console.log("a is 40"); } else if (a === 311) { console.log("a is 311"); } else if (a === 422) { console.log("a is 422"); } else if (a === 333) { console.log("a is 333"); } else if (a === 444) { console.log("a is 444"); } else if (a === 355) { console.log("a is 355"); } else if (a === 2) { console.log("a is 2"); } else if (a === 1) { console.log("a is 1"); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Switch case
if-else

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36

Browser/OS: Chrome 124 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Switch case	347742.4 Ops/sec
if-else	339014.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into explaining the benchmark.

**Benchmark Overview**

The provided benchmark compares two approaches to handle multiple conditions: `switch case` and `if-else`. The goal is to determine which approach is faster in terms of execution time.

**Switch Case**

In this approach, we use a `switch` statement to check the value of `a` against various cases. Each case has a specific code block that will be executed if the condition matches.

Example:
```javascript
const a = 1;
switch (a) {
    case 5:
        console.log("a is 5");
        break;
    case 4:
        console.log("a is 4");
        break;
    // ...
}
```
**Pros:**

* Efficient use of memory, as the compiler can optimize away unnecessary code blocks.
* Can handle multiple conditions in a single statement.

**Cons:**

* Requires explicit `break` statements to exit the switch block, which can lead to mistakes if not used carefully.
* May be slower due to the need for a jump table or fall-through optimization by the JavaScript engine.

**If-Else**

In this approach, we use multiple `if` statements chained together using `else if`. Each condition is checked in sequence until one matches.

Example:
```javascript
const a = 1;
if (a === 5) {
    console.log("a is 5");
} else if (a === 4) {
    console.log("a is 4");
} // ...
```
**Pros:**

* Easy to read and write, as each condition is self-contained.
* Does not require explicit `break` statements.

**Cons:**

* Can be slower due to the need for multiple checks and potential branch prediction errors.
* Requires more memory allocations for temporary variables and stack frames.

**Library Used:**

The benchmark does not explicitly use any libraries. However, it's worth noting that modern JavaScript engines, including those used by Chrome, have various optimizations and features like Just-In-Time (JIT) compilation, which can affect the performance of these approaches.

**Special JS Feature/Syntax:**

There are no special JavaScript features or syntaxes mentioned in this benchmark. However, it's essential to consider factors like function call overhead, loop unrolling, and cache locality when optimizing code for performance.

**Benchmark Results:**

The latest benchmark results show that Chrome 124 on a Mac OS X 10.15.7 Desktop is executing the `switch case` approach (347742.375 executions per second) faster than the `if-else` approach (339014.4375 executions per second). However, please note that these results may not reflect your specific environment or browser version.

Keep in mind that this benchmark is a simple example and may not accurately represent real-world use cases. More complex scenarios might require different optimization strategies.

Related benchmarks:

if-else vs switch case (version: 0)

Comparing performance of: Switch case vs if-else

Created: 3 years ago by: Guest

Jump to the latest result

Switch case

if-else

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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