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For loop bench
(version: 0)
Benchmark.js
Comparing performance of:
for - vs for +
Created:
4 years ago
by:
Guest
Go to the latest result
Tests:
for -
var payload=['apple','banana','mango'] for(var key = payload.length-1; key >=0 ; key--){ console.log(payload[key]); }
for +
var payload=['apple','banana','mango'] for(var key = payload; key > payload.length ; key++){ console.log(payload[key]); }
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
for -
for +
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
one year ago
)
User agent:
Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Mobile Safari/537.36
Browser/OS:
Chrome Mobile 131 on Android
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Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=578879" width="100%" height="500px"></iframe>
for +
1.7M/s
for -
21K/s
View exact numbers
Test name
Executions per second
✓
for +
1,721,398 Ops/sec
for -
21,466 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
I'll explain the benchmark in a clear and concise manner. **Benchmark Overview** The benchmark is designed to measure the performance of two different approaches for iterating over an array in JavaScript. The goal is to determine which approach is faster. **Test Cases** There are two test cases: 1. **"for -"`**: This test case uses a traditional `for` loop with a decrementing index variable (`key`) to iterate over the elements of an array. Specifically, it starts from the last element and iterates backwards to the first element. 2. **"for +"`**: This test case uses a non-traditional `for` loop that increments the index variable directly, effectively starting from the last element and iterating forwards to the first element. **Comparison of Approaches** The two approaches differ in their syntax and execution behavior: * **Traditional `for` loop (`"for -"`)**: This approach is more common and well-established. It uses a decrementing index variable to iterate over the elements, which can lead to more predictable performance. * **Non-traditional `for` loop (`"for +"`)**: This approach is less common and may require more careful handling of edge cases. It increments the index variable directly, which can lead to fewer iterations but also more potential for errors. **Pros and Cons** Here are some pros and cons of each approach: * **Traditional `for` loop (`"for -"`**: + Pros: More predictable performance, less prone to errors. + Cons: May use more memory due to the need to store the index variable. * **Non-traditional `for` loop (`"for +"`**: + Pros: Fewer iterations, potentially faster performance in certain cases. + Cons: Less predictable performance, more prone to errors if not handled carefully. **Library Usage** There is no explicit library usage in this benchmark. However, some JavaScript engines may optimize or implement specific optimizations for array iteration, such as: * **ES6 Array.prototype.forEach()**: This method provides a more concise and expressive way of iterating over arrays, but it may not be directly comparable to the traditional `for` loop. * **WebAssembly (WASM)**: This standard provides a binary format for executing code in web browsers. Some JavaScript engines may use WASM to optimize array iteration. **Special JS Feature/Syntax** There are no special JS features or syntax used in this benchmark. **Other Alternatives** Some alternative approaches for iterating over arrays include: * **Array.prototype.forEach()**: As mentioned earlier, this method provides a more concise and expressive way of iterating over arrays. * **While loops**: This approach can be useful when the number of iterations is not known beforehand or when a specific condition needs to be met during iteration. In summary, the benchmark compares two traditional `for` loop approaches for array iteration: one with a decrementing index variable (`"for -"`**) and another that increments the index variable directly (`"for +"`**). The choice of approach depends on performance requirements, code readability, and maintainability.
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