Benchmark: Test for and for reverse

Tests:

normal
let tmp; const someNumbers = [1,2,3,4,5,6,7,8,9,10]; const l = someNumbers.length; for (let p = 0; p < 1000; ++p){ for(let i = 0; i<l; ++i){ tmp = someNumbers[i]; } }
reverse
let tmp; const someNumbers = [1,2,3,4,5,6,7,8,9,10]; const l = someNumbers.length - 1; for (let p = 0; p < 1000; ++p){ for(let i = l; i>=0; --i){ tmp = someNumbers[i]; } }
another
let tmp; const someNumbers = [1,2,3,4,5,6,7,8,9,10]; for (let p = 0; p < 1000; ++p){ for(let i =0; tmp= someNumbers[i]; ++i){ } }
while
let tmp; const someNumbers = [1,2,3,4,5,6,7,8,9,10]; const l = someNumbers.length; let p = 0; while(p<100){ let i = 0; ++p; while(i<l){ tmp = someNumbers[i]; ++i; } };
while reverse
let tmp; const someNumbers = [1,2,3,4,5,6,7,8,9,10]; const l = someNumbers.length; let p = 101; while(p){ let i = l; --p; while(i){ tmp = someNumbers[--i]; } };
while other
let tmp; const someNumbers = [1,2,3,4,5,6,7,8,9,10]; const l = someNumbers.length; let p = 0; while(p<100){ let i = 0; p += 1; while(i<l){ tmp = someNumbers[i]; i+=1; } };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
normal
reverse
another
while
while reverse
while other

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:85.0) Gecko/20100101 Firefox/85.0

Browser/OS: Firefox 85 on Windows

View result in a separate tab

Test name	Executions per second
normal	71098.5 Ops/sec
reverse	85853.9 Ops/sec
another	40424.8 Ops/sec
while	860596.1 Ops/sec
while reverse	594385.2 Ops/sec
while other	859684.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring the performance of JavaScript loops is a complex task, and MeasurThat.net provides a valuable service by helping us understand how different browsers and architectures handle these types of loops.

The provided benchmark tests six different loop structures:

1. **Normal Loop**: A traditional `for` loop with a decrementing index.
2. **Reverse Loop**: A `for` loop with an incrementing index, starting from the last element of the array.
3. **Another Loop**: A loop with a single line assignment to the variable `tmp`, followed by an incrementing index.
4. **While Loop**: A `while` loop that iterates until a condition is met.
5. **Reverse While Loop**: A `while` loop with a decrementing index, starting from the last element of the array.
6. **Other While Loop**: A `while` loop with an incrementing index, but without assigning a value to `tmp`.

Let's analyze each approach:

**Pros and Cons:**

*   **Normal Loop (1)**:
    *   Pros: Simple and well-understood by most developers.
    *   Cons: May be slower due to the overhead of incrementing the index variable.
*   **Reverse Loop (2)**:
    *   Pros: Can be faster because the loop starts from the last element, reducing the number of iterations.
    *   Cons: Requires careful consideration to avoid accessing out-of-bounds indices.
*   **Another Loop (3)**:
    *   Pros: Simple and concise, but may lead to performance issues due to the single line assignment.
    *   Cons: Can be harder to understand and debug for complex loops.
*   **While Loop (4) / Other While Loop (6)**:
    *   Pros: Allows for more flexibility in the loop condition and can be faster because it avoids the overhead of incrementing an index variable.
    *   Cons: Requires careful consideration of the loop condition to avoid infinite loops or missing iterations.

**Library Usage:**

None of the provided benchmark definitions explicitly use any external libraries. However, some browsers (e.g., Firefox) may include additional functionality in their JavaScript engines that could affect the performance of these loops. MeasurThat.net's results are likely influenced by these internal optimizations.

**Special JS Features or Syntax:**

None of the provided benchmark definitions use special JavaScript features like `let`, `const`, or arrow functions, which are supported in modern browsers. These features do not seem to impact the performance of these specific loops.

In summary, MeasurThat.net's benchmark results highlight the importance of considering different loop structures when writing efficient JavaScript code. While traditional `for` loops may be simple to understand and implement, other approaches like reverse loops or while loops can offer performance benefits in certain cases. It is essential to weigh the trade-offs between readability, maintainability, and performance when choosing the best loop structure for a particular problem.

Related benchmarks:

Test for and for reverse (version: 9)

Comparing performance of: normal vs reverse vs another vs while vs while reverse vs while other

Created: 3 years ago by: Registered User

Jump to the latest result

normal

reverse

another

while

while reverse

while other

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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