Benchmark: switch vs if - MeasureThat.net

HTML Preparation code:

<div class="test"></div>

Script Preparation code:

var v = 8;

Tests:

switch
switch (true) { case v === 1: break; case v === 2: break; case v === 3: break; case v === 4: break; case v === 5: break; case v === 6: break; case v === 7: break; default: ; }
if
if (v === 1) { } else if (v === 2) { } else if (v === 3) { } else if (v === 4) { } else if (v === 5) { } else if (v === 6) { } else if (v === 7) { } else if (v === 8) { } else { }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
switch
if

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:143.0) Gecko/20100101 Firefox/143.0

Browser/OS: Firefox 143 on Windows

View result in a separate tab

Test name	Executions per second
switch	42150480.0 Ops/sec
if	37148368.0 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 using a `switch` statement versus a chain of `if...else if` statements in JavaScript to check against various values.

**Options Compared:**

* **`switch` Statement:** This evaluates an expression and executes the code block associated with the matching case. In this example, each `case` checks if the variable `v` equals a specific number (1 through 8). If no match is found, it executes the `default` block.
* **Chain of `if...else if` Statements:** This sequentially checks conditions. Each `if` statement evaluates to true or false, and if true, its code block is executed.  If none are true, the final `else` block executes. Here, each `if` statement checks if `v` equals a specific number (1 through 8).

**Pros and Cons:**

* **`switch` Statement:**
    * **Pros:** Generally faster for many cases because it uses a jump table optimization under the hood. Can be more concise when dealing with multiple comparisons against distinct values.
    * **Cons:**  Can become less readable if you have a large number of cases. It's not ideal for complex conditional logic that involves logical operators or nested conditions.

* **Chain of `if...else if` Statements:**
    * **Pros:** More flexible for complex conditions involving multiple checks, logical operators, etc. Easier to read for simple cases with few comparisons.
    * **Cons:**  Can be slower than `switch` when you have many cases because each condition needs to be evaluated sequentially.

**Other Considerations:**

* **Compiler Optimizations:** Modern JavaScript engines often perform optimizations that can significantly impact the performance difference between `switch` and `if...else if`.

* **Benchmarking Context:** The results of this benchmark are specific to the test environment (Chrome 65 on Linux) and may vary on different browsers, operating systems, or hardware.

**Alternatives:**

While not directly tested in this example:

* **`Object`-Based Lookup:**  Use an object where keys are the values you're checking for, and values are the associated code to execute. This can be more performant than `switch` or `if...else if` chains for a large number of cases.

Let me know if you have any other questions!

Related benchmarks:

switch vs if (version: 0)

Comparing performance of: switch vs if

Created: 8 years ago by: Guest

Jump to the latest result

switch

if

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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