Benchmark: if vs switch case

Tests:

switch case
function thing(j) { switch(j) { case 0: case 1: case 2: case 3: return 1; case 10: case 11: case 12: case 13: return 2; case 24: case 25: case 26: case 27: return 3; default: return 0; } } let sum = 0 for(let i = 0; i < 100000; i++) { for(let j = 0; j < 32; j++) { sum += thing(j); } } console.log(sum);
jump table
function thing(j) { if(j == 0) return 1; if(j == 1) return 1; if(j == 2) return 1; if(j == 3) return 1; if(j == 10) return 2; if(j == 11) return 2; if(j == 12) return 2; if(j == 13) return 2; if(j == 24) return 3; if(j == 25) return 3; if(j == 26) return 3; if(j == 27) return 3; return 0; } let sum = 0 for(let i = 0; i < 100000; i++) { for(let j = 0; j < 32; j++) { sum += thing(j); } } console.log(sum);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
switch case
jump table

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/129.0.0.0 Safari/537.36

Browser/OS: Chrome 129 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
switch case	158.2 Ops/sec
jump table	157.3 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

The provided JSON represents two test cases for comparing the performance of `if` statements and switch case statements in JavaScript.

**Benchmark Definition:**

The benchmark definition is a function named `thing(j)` that takes an integer `j` as input. The function uses both `if` statements and switch case statements to determine the return value based on the value of `j`. There are four cases:

*   For `j` values 0, 1, 2, or 3, it returns 1.
*   For `j` values 10, 11, 12, 13, 24, 25, 26, or 27, it returns 2.
*   For all other cases (including those not explicitly mentioned), it returns 0.

**Test Case Options:**

The benchmark compares the performance of two options:

1.  **Switch Case Statement:** The first test case uses a switch case statement to determine the return value based on the value of `j`.
2.  **Jump Table Approach:** The second test case uses a jump table approach, where it uses multiple if-conditional statements to achieve similar functionality.

**Pros and Cons:**

### Switch Case Statement:

Pros:

*   Easier to read and maintain due to its concise syntax.
*   Can be more efficient for small numbers of cases.

Cons:

*   Can lead to slower performance for large numbers of cases or when the number of cases grows rapidly.

### Jump Table Approach:

Pros:

*   Generally provides faster execution times, especially for larger ranges of values.
*   Allows for easy modification and addition of new case values without affecting existing code.

Cons:

*   More verbose and harder to read due to the need for multiple if-conditional statements.
*   Can be more error-prone when dealing with edge cases or incorrect case assignments.

**Library Considerations:**

In this benchmark, there is no explicit mention of any libraries. However, some modern JavaScript implementations (like V8 in Google Chrome) have built-in optimizations and features that can affect the performance of switch statements, such as:

*   **Switch Table Optimizations:** Modern engines like V8 use precomputed switch tables to improve performance.
*   **Tail Call Optimization:** Some engines optimize tail calls, which can reduce overhead for recursive functions.

**Special JavaScript Features:**

There are no special JavaScript features explicitly mentioned in the benchmark. However, some features that might impact performance or optimization include:

*   **Generator Functions:** While not directly relevant to this benchmark, generator functions can provide additional optimizations for loops and iterations.
*   **Async/Await Syntax:** This syntax is not directly applicable to this specific benchmark but may be relevant when dealing with asynchronous code.

**Other Alternatives:**

If you're interested in exploring alternative approaches to switch case statements or jump tables, consider the following options:

1.  **Object-Oriented Programming (OOP):** You can use objects and their methods to achieve similar functionality, although this might not be as concise or efficient.
2.  **Functional Programming:** Techniques like higher-order functions, currying, or using `Array.prototype.includes()` can provide an alternative to switch statements.
3.  **Regex-Based Solutions:** Using regular expressions to match specific patterns can offer a unique approach to handling different cases.

For the provided benchmark, if you want to experiment with alternative approaches, consider exploring other options like those mentioned above.

Related benchmarks:

if vs switch case (version: 0)

Comparing performance of: switch case vs jump table

Created: 3 years ago by: Guest

Jump to the latest result

switch case

jump table

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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