Benchmark: if/else vs. small switch

Script Preparation code:

const a = 1;
let b;

Tests:

switch
switch(a) { case 0: b = 1; break; case 1: b = 2; break; default: b = 3; }
if/else
if (a === 0) { b = 1; } else if (a === 1) { b = 2; } else { b = 3; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
switch
if/else

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 16 days ago):

LLMs can make mistakes. Check important info.

The benchmark presented compares two approaches to conditional logic in JavaScript: using `switch` statements versus `if/else` statements. In the context of JavaScript programming, both structures are commonly used to execute different branches of code based on the value of a variable.

### Options Compared

1. **`switch` Statement**:
   - **Test Case**:
     ```javascript
     switch(a) {
         case 0:
             b = 1;
             break;
         case 1:
             b = 2;
             break;
         default:
             b = 3;
     }
     ```
   - This code evaluates the variable `a` against multiple cases. Depending on the value of `a`, it assigns different values to `b`. The `switch` statement can simplify scenarios with multiple potential values for a single variable, making it clearer and easier to read in some contexts.

2. **`if/else` Statement**:
   - **Test Case**:
     ```javascript
     if (a === 0) {
         b = 1;
     } else if (a === 1) {
         b = 2;
     } else {
         b = 3;
     }
     ```
   - The `if/else` pattern checks conditions sequentially. If the condition of `if` is true, it executes a block of code; if not, it checks the next `else if`, and so on. This method provides flexibility and allows the use of more complex conditional expressions.

### Pros and Cons

- **`switch` Pros**:
  - Can be more concise and readable when dealing with a single variable that can take multiple discrete values.
  - Avoids deep nesting of conditional blocks, reducing cognitive load.

- **`switch` Cons**:
  - Tends to be less flexible than `if/else`, as it can only evaluate expressions based on equality.
  - May lead to fall-through behavior (if `break` statements are omitted), which can introduce bugs if not handled carefully.

- **`if/else` Pros**:
  - More versatile, as it can handle complex conditions (e.g., ranges, multiple variables).
  - Easier to understand for those familiar with straightforward linear logic.

- **`if/else` Cons**:
  - Can become cumbersome and hard to read when multiple conditions are checked sequentially, especially with deep nesting.

### Benchmark Results

The benchmark results indicate that in the given JavaScript environment (Chrome 130 on Windows), the `switch` statement achieved approximately **82,908,912 executions per second**, while the `if/else` statement achieved about **70,612,552 executions per second**. This suggests that the `switch` statement may be slightly more performant for this specific case, likely due to optimizations in the JavaScript engine that can handle `switch` more efficiently in certain structures.

### Other Considerations and Alternatives

1. **Performance Variability**: The performance of `switch` versus `if/else` can differ significantly based on the JavaScript engine (e.g., V8 in Chrome, SpiderMonkey in Firefox) and the specific use case. It's essential to test in the targeted environment.

2. **Alternative Constructs**:
   - **Lookup Tables**: In scenarios with fixed mappings of inputs to outputs, consider using a lookup object or array. This can be faster than both `switch` and `if/else` in some situations.
   - **Ternary Operator**: For very simple conditions, a ternary operator may be suitable, though readability can suffer in more complex situations.

3. **Modern Syntax**: With the advent of modern JavaScript (ES6 and later), other constructs like `Map` and functional programming techniques (e.g., using arrays of functions) may also be suitable for handling conditional logic, based on the problem domain.

In summary, the choice between using a `switch` statement and `if/else` should consider readability, maintainability, and performance based on your specific use case and the JavaScript engine in use. It's often based on the developer's preference, the complexity of conditions, and the intended use case.

Latest run results:

Run details: (Test run date: 3 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36 Edg/130.0.0.0

Browser/OS: Chrome 130 on Windows

View result in a separate tab

Test name	Executions per second
switch	10078432.0 Ops/sec
if/else	10031389.0 Ops/sec

Related benchmarks:

if/else vs. small switch (version: 1)

Comparing performance of: switch vs if/else

Created: 16 days ago by: Guest

Jump to the latest result

switch

if/else

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 16 days ago):