Benchmark: if-else vs switch

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 == 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 case
if-else

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36

Browser/OS: Chrome 146 on Linux

View result in a separate tab

Test name	Executions per second
Switch case	262429.9 Ops/sec
if-else	266165.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is crucial for optimizing code, and MeasuringThat.net provides an excellent platform for doing so.

**Benchmark Overview**

The provided benchmark compares the performance of `if-else` statements with `switch` statements in JavaScript. The test case uses a constant value of 1 (a) and checks if it matches specific values using both approaches.

**Options Compared**

Two options are compared:

### Switch Statement

In the switch statement, we check for multiple cases without repeating conditionals like this:
```javascript
case 5:
    console.log("a is 5");
break;
case 4:
    console.log("a is 4");
break;
...
```
**Pros:**

1.  Reduces repetition of conditions.
2.  Can improve readability.

**Cons:**

1.  May have a performance overhead due to the extra operations required for falling through cases.
2.  If not used carefully, it can make code harder to read if there are many cases that fall through the same set of next statements.

### If-Else Statement

For comparison, we use multiple `if-else` statements with repeated conditionals:
```javascript
if (a == 5) {
    console.log("a is 5");
} else if (a == 4) {
    console.log("a is 4");
} else ...
```
**Pros:**

1.  Can be faster in some cases, since there are fewer operations.

**Cons:**

1.  Code can become repetitive and harder to read.
2.  May lead to more complex logic for handling multiple conditions.

**Library Used**

There isn't an explicit library mentioned in the benchmark definition provided.

**Special JS Feature/Syntax**

The benchmark uses JavaScript conditionals (if-else, switch), which are a fundamental aspect of the language.

**Other Considerations**

1.  **Variable Number of Cases**: The number of cases used in this example is quite large, making it harder to compare results accurately.
2.  **Execution Per Second**: Execution speed can be influenced by many factors beyond just code complexity and syntax (e.g., browser performance optimizations, hardware capabilities).
3.  **Browser vs Device Platform**: Results might vary between browsers or devices due to different engine implementations or hardware differences.

**Alternatives**

If this benchmark is for a specific use case where both if-else and switch statements are being used, here are some alternatives to consider:

1.  For repeated conditions (like in the if-else example), you could create an object with condition values mapped to their respective actions:
    ```javascript
const conditionalActions = {
    5: () => console.log("a is 5"),
    4: () => console.log("a is 4"),
};
if (a in conditionalActions) conditionalActions[a]();
```
2.  For more cases or complex conditions, you might want to consider using a more advanced data structure like an array of objects and applying `forEach`:
    ```javascript
const conditions = [
    { value: 5, action: () => console.log("a is 5") },
    { value: 4, action: () => console.log("a is 4") },
];
conditions.forEach(condition => condition.action());
```
3.  When dealing with a large number of cases (as in this benchmark), you might want to explore more optimized switch statement implementations or consider using a pre-compiled version for performance.

These alternatives might offer better readability, maintainability, and performance depending on your specific requirements and constraints. Always profile and test different approaches before deciding on an implementation strategy.

Related benchmarks:

if-else vs switch (version: 0)

Comparing performance of: Switch case vs if-else

Created: 4 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):