Benchmark: JS if/if vs if/else if vs switch

Script Preparation code:

var test = 'test'

Tests:

if/if
if (test === 'test1') { return 1; } if (test === 'test2') { return 2; } if (test === 'test3') { return 3; } if (test === 'test4') { return 4; } if (test === 'test5') { return 5; }
if/else if
if (test === 'test1') { return 1; } else if (test === 'test2') { return 2; } else if (test === 'test3') { return 3; } else if (test === 'test4') { return 4; } else if (test === 'test5') { return 5; }
switch case
switch (test) { case 'test1': return 1; case 'test2': return 2; case 'test3': return 3; case 'test4': return 4; case 'test5': return 5; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
if/if
if/else if
switch case

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 28 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36 Edg/146.0.0.0

Browser/OS: Chrome 146 on Windows

View result in a separate tab

Test name	Executions per second
if/if	104835888.0 Ops/sec
if/else if	110078568.0 Ops/sec
switch case	108546736.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring the performance of different JavaScript control flow structures is crucial for optimizing code and ensuring efficient execution.

The provided benchmark compares three approaches:

1. **Multiple `if` statements**: This approach uses separate conditional checks for each possible value of the `test` variable. The code checks if `test` equals one of the five values, and returns a corresponding result.
2. **`if/else if` chain**: In this approach, the code uses an `if/else if` chain to check multiple conditions in a single sequence. The conditions are evaluated from top to bottom, and each condition is short-circuited if it's not met.
3. **`switch` statement**: This approach uses a `switch` statement to check the value of `test` against multiple cases. Each case has an associated code block that will be executed if the test value matches.

**Pros and Cons:**

* **Multiple `if` statements**:
	+ Pros: Easy to understand, concise code.
	+ Cons: Can lead to slow performance due to repeated checks.
* **`if/else if` chain**:
	+ Pros: Efficient in terms of execution time, as conditions are short-circuited.
	+ Cons: More complex to read and write, especially for longer chains.
* **`switch` statement**:
	+ Pros: Can be faster than `if/else if` chains for large numbers of cases, as it uses a jump table.
	+ Cons: May require more memory allocation for the switch table.

The `switch` statement is currently outperforming both the `if/if` and `if/else if` approaches in this benchmark. This makes sense, given that `switch` statements can use a jump table to quickly determine which case to execute.

**Library usage:**

There are no libraries used in the provided benchmark code. However, some JavaScript implementations might use internal optimizations or built-in functions that could affect performance.

**Special JavaScript features/syntax:**

This benchmark doesn't explicitly test any special JavaScript features or syntax, such as async/await, generators, or arrow functions. It primarily focuses on the control flow structures themselves.

**Alternative approaches:**

Some alternative approaches to consider:

* **`ternary operator` (conditional operator)**: Instead of using multiple `if` statements or an `if/else if` chain, you could use a ternary operator to simplify the code.
* **`Object.keys()` and `Array.prototype.forEach()`**: For large datasets, you might consider using an object with keys representing values and iterating over it using `Array.prototype.forEach()`. This approach would eliminate the need for explicit loops or conditional checks.
* **`const` and `let` optimization**: In some cases, using `const` instead of `var` can help optimize performance by reducing the time it takes to reassign variables.

However, these alternative approaches are not directly related to the control flow structures being tested in this benchmark.

Related benchmarks:

JS if/if vs if/else if vs switch (version: 0)

Benchmark of the speed difference between using multiple IF statements and an open-ended IF/ELSE IF.

Comparing performance of: if/if vs if/else if vs switch case

Created: 3 years ago by: Guest

Jump to the latest result

if/if

if/else if

switch case

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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