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slice array
(version: 0)
slice array to get sub array
Comparing performance of:
for loop vs slice
Created:
5 years ago
by:
Guest
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Script Preparation code:
var data =[]; for(var i=0;i<1000;i++){var row=[];for(var j=0;j<1000;j++) {row[j]=i*j;} data[i]=row;}
Tests:
for loop
var xdata=[];for(var i=0;i<800;i++) {xdata[i]=data[200][i]};
slice
var xdata=[];xdata=data[200].slice(0,800);
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
for loop
slice
Fastest:
N/A
Slowest:
N/A
Latest run results:
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the provided benchmark definition and test cases to understand what is being tested. **Benchmark Definition** The benchmark measures how fast two different approaches are to slice an array in JavaScript: 1. **Preparation Code**: The script prepares an array `data` with 1000 rows, each containing 1000 elements. This array will be used for slicing. 2. **HTML Preparation Code**: There is no HTML preparation code provided. **Options being compared** The benchmark compares two approaches to slice the `data` array: 1. **For Loop (Test Name: "for loop")**: The first test uses a traditional for loop to extract a subset of 800 elements from the middle row (index 200) of the original array. 2. **Slice Method (Test Name: "slice")**: The second test uses the built-in `Array.prototype.slice()` method to extract the same subset of 800 elements. **Pros and Cons** 1. **For Loop**: * Pros: Can be used for more complex data manipulation, allows for dynamic indexing. * Cons: Can be slower due to the overhead of the loop and potential index out-of-bounds errors. 2. **Slice Method**: * Pros: Faster, more concise, and safer (less prone to index out-of-bounds errors). * Cons: May not work as expected if the array is modified or has a non-numeric length. **Library usage** There is no explicit library usage in this benchmark definition. **Special JS feature/syntax** The benchmark does not use any special JavaScript features or syntax. **Alternatives** If you were to modify the benchmark, you could consider adding other approaches to slice an array, such as: * Using `Array.prototype.map()` and `Array.prototype.slice()` * Utilizing modern JavaScript features like `flatMap()` (if available) * Implementing a custom slicing function using recursion or memoization * Examining performance differences with specific data structures, like sparse arrays Keep in mind that the choice of approach depends on the use case and requirements of your project. **Additional Considerations** When running this benchmark: * Make sure to clear any cache or cookies before running the test. * Ensure the browser is up-to-date and patched against any security vulnerabilities. * Run the test multiple times to ensure accurate results, as individual runs may not be representative of real-world performance.
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