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Test push, spread, concat
(version: 0)
Comparing performance of:
push vs concat vs spread
Created:
8 years ago
by:
Guest
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Tests:
push
let first = []; let second = []; for (var i; i < 100; i++) { first.push(i); second.push(i); } first.push(...second);
concat
let first = []; let second = []; for (var i; i < 100; i++) { first.push(i); second.push(i); } first = first.concat(second);
spread
let first = []; let second = []; for (var i; i < 100; i++) { first.push(i); second.push(i); } first = [...first, ...second];
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (3)
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Test case name
Result
push
concat
spread
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net. **Benchmark Definition** The provided JSON represents a benchmark definition for a set of test cases that compare three different approaches to merge two arrays: `push` with spread operator (`...`), `concat()`, and array spreading using the spread operator (`[...first, ...second]`). The benchmark aims to measure which approach is the fastest. **Options Compared** 1. **Push**: This method uses the `push()` method to add elements to an array. It's a simple and straightforward way to append elements. 2. **Concat()**: This method uses the `concat()` method to merge two arrays. It creates a new array by concatenating the two input arrays. 3. **Spread Operator (`...`)**: This method uses the spread operator to create a new array by spreading the elements of one or more arrays. **Pros and Cons** * **Push**: Pros: Simple, fast, and widely supported. Cons: Can be slower for large arrays due to the overhead of multiple `push()` calls. * **Concat()**: Pros: Creates a new array, allowing for caching and reusing. Cons: Slower than `push` because it creates a new array, and it can lead to performance issues with large arrays. * **Spread Operator (`...`)**: Pros: Fast, efficient, and modern. Cons: Requires support for the spread operator (introduced in ECMAScript 2015), which might not be available in older browsers or environments. **Library Usage** None of these approaches rely on external libraries. However, if you're interested in exploring other options that involve libraries, some benchmarks compare implementations with libraries like Lodash or Underscore.js. **Special JS Features or Syntax** None of the benchmarked features require special JavaScript features or syntax beyond ECMAScript 2015 (for the spread operator). **Other Considerations** * **Cache**: The `concat()` method is more likely to benefit from caching because it creates a new array, allowing for reuse. In contrast, `push` and the spread operator might not be optimized for caching due to their specific use cases. * **Garbage Collection**: For large arrays, garbage collection can become an issue with `push`, as each push operation may allocate new memory without reusing existing memory. The spread operator mitigates this issue by creating a new array, while `concat()` also avoids reallocations but might lead to slower performance due to the overhead of function calls. **Alternative Approaches** * **Array.from()**: This method uses an array constructor (`Array.from()`) to create a new array from an iterable. While it's not directly comparable to our benchmarked approaches, it can be another option for creating arrays. * **Using `slice()` and `concat()`**: Another alternative is using the `slice()` method followed by `concat()`. This approach can offer better cache locality than the spread operator. In conclusion, understanding these different array merge approaches will help you write more efficient JavaScript code. By considering factors like caching, garbage collection, and performance optimizations, you'll be able to choose the best approach for your specific use cases.
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Concat vs Push vs Spread Benchmark
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