Benchmark: switch(true) vs if-else

Tests:

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

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 11 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
switch(true)	384345.6 Ops/sec
if-else	376402.4 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and provide an analysis of the results.

**Benchmark Overview**

The benchmark measures the performance difference between using a `switch` statement with a conditional expression (`true`) versus an `if-else` chain in JavaScript. The test cases are identical, except for the syntax used.

**Switch Statement (with true)**

In this approach, the `switch` statement is used to evaluate the condition `a === 5`. Since `true` is always evaluated as true, the entire `switch` block will be executed for each case that matches. However, in this specific test case, none of the cases match, so the `switch` block will still be executed but with no branching.

**If-Else Chain**

In this approach, an `if-else` chain is used to evaluate the condition `a == 5`. The first matching case will be executed if true. However, in this test case, there are multiple consecutive `if-else` statements that all match when `a == 3`, which is a different value than what we want to check.

**Pros and Cons**

* **Switch Statement (with true)**:
	+ Pros: Can potentially execute faster due to the conditional expression being evaluated once.
	+ Cons: May execute more code than necessary since none of the cases match.
* **If-Else Chain**:
	+ Pros: Executes only when a condition is met, which can be beneficial for performance in some scenarios.
	+ Cons: Can lead to slower execution due to the multiple consecutive checks.

**Library and Special JS Features**

There are no libraries mentioned in the benchmark definition. However, it's worth noting that modern JavaScript engines often have optimizations and heuristics to improve performance in such cases.

**Test Results**

The latest benchmark results show:

* **Switch (with true)**: Executions per second = 384345.5625
* **If-Else**: Executions per second = 376402.40625

The results suggest that the `switch` statement with a conditional expression (`true`) is slightly faster than the `if-else` chain in this specific test case.

**Other Alternatives**

Other alternatives for evaluating simple conditions in JavaScript include:

* Using the ternary operator (`?:`)
* Using `&&` and `||` operators
* Using `===` or `==` comparisons with a conditional expression

However, these alternatives may not provide the same level of readability and maintainability as the `if-else` chain used in this benchmark.

In conclusion, the results suggest that the `switch` statement with a conditional expression (`true`) is slightly faster than the `if-else` chain in this specific test case. However, the performance difference may not be significant enough to justify using this approach in most scenarios.

Related benchmarks:

switch(true) vs if-else (version: 0)

Comparing performance of: switch(true) vs if-else

Created: 11 months ago by: Guest

Jump to the latest result

switch(true)

if-else

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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