Benchmark: Conditional slicing

Script Preparation code:

var string = "abcdefghijklmnopqrstuvwxyz"

Tests:

slice
var copy = string.slice(0, 30);
with condition
var copy = string.length > 30 ? string.slice(0, 30): string;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
with condition

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/132.0.0.0 Safari/537.36

Browser/OS: Chrome 132 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
slice	190700560.0 Ops/sec
with condition	161359728.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):

LLMs can make mistakes. Check important info.

The benchmark in question, titled "Conditional slicing," evaluates the performance of two different approaches to slicing a string in JavaScript. The string being tested is `"abcdefghijklmnopqrstuvwxyz"`.

### Test Cases

1. **Test Case 1: Simple Slice**
   - **Benchmark Definition**: `var copy = string.slice(0, 30);`
   - **Test Name**: "slice"
   
   This test case utilizes the built-in JavaScript String method `slice()`, which extracts a portion of a string based on the specified start and end indices. In this case, it attempts to slice from index 0 to 30. Since the original string is only 26 characters long, the method will return the entire string.

2. **Test Case 2: Conditional Slice**
   - **Benchmark Definition**: `var copy = string.length > 30 ? string.slice(0, 30): string;`
   - **Test Name**: "with condition"
   
   This test case introduces a conditional (ternary) operator that checks if the length of the string is greater than 30. If true, it slices the string; otherwise, it returns the entire string. Given that the string's actual length is 26, this will always return the string in this scenario.

### Performance Results

From the latest benchmark results, we see:
- For the "slice" test, the executions per second were **190,700,560**.
- For the "with condition" test, the executions per second were **161,359,728**.

### Comparison of Options

- **Pros and Cons**:
  - **Simple Slice**:
    - **Pros**: Direct and straightforward. No additional checks, leading to potentially faster execution in cases where the slice is applied.
    - **Cons**: May lead to unnecessary processing if it is assumed that string lengths will frequently exceed the specified slice.
    
  - **Conditional Slice**:
    - **Pros**: It adds a level of safety to ensure you're only slicing when it makes sense, potentially reducing errors when dealing with variable-length strings.
    - **Cons**: It introduces additional logic (the conditional check), which can slow down performance, especially if used repeatedly in a tight loop or high-frequency calls.

### Other Considerations

- **Execution Timing**: The difference in performance suggests that unnecessary conditional checks can lead to slower execution speeds, particularly in performance-critical applications. However, the actual difference in this case is not very large and may or may not be significant depending on the use case.
  
- **Alternative Approaches**: 
  - An alternative might be to use `substring()` or `substr()`, which can also extract portions of a string. The performance of these methods can vary based on the implementation, but they follow similar principles.
  - Depending on use cases, developers may also consider other data structures or libraries (like using arrays or typed arrays) for managing collections of characters, although this would change the underlying logic and intent of string manipulation.

Overall, the benchmark provides insight into how seemingly minor differences in approach can impact performance and how best practices must strike a balance between safety and efficiency.

Related benchmarks:

Conditional slicing (version: 1)

Comparing performance of: slice vs with condition

Created: one year ago by: Guest

Jump to the latest result

slice

with condition

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):