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test different concat methods
(version: 0)
Comparing performance of:
concat vs spread vs push
Created:
2 years ago
by:
Guest
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Tests:
concat
const a1 = [ { a: 123, b: 'qwe' }, { a: 45, b: 'sdf' }, { a: 44, b: '2dfs' } ] const a2 = [ { a: 678, b: 'bddbxd' }, { a: 3, b: 'ssgfgfdf' }, { a: 454, b: '2sdfdfs' } ] const other = a1.concat(a2)
spread
const a1 = [ { a: 123, b: 'qwe' }, { a: 45, b: 'sdf' }, { a: 44, b: '2dfs' } ] const a2 = [ { a: 678, b: 'bddbxd' }, { a: 3, b: 'ssgfgfdf' }, { a: 454, b: '2sdfdfs' } ] const other = [...a1, ...a2]
push
const a1 = [ { a: 123, b: 'qwe' }, { a: 45, b: 'sdf' }, { a: 44, b: '2dfs' } ] const a2 = [ { a: 678, b: 'bddbxd' }, { a: 3, b: 'ssgfgfdf' }, { a: 454, b: '2sdfdfs' } ] a1.push(...a2)
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Test case name
Result
concat
spread
push
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N/A
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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 Overview** The benchmark compares three different methods for concatenating arrays in JavaScript: `concat`, spread operator (`...`), and `push` with an array spread syntax (`a1.push(...a2)`). The goal is to determine which method is the fastest, most efficient, or most scalable for joining two arrays. **Benchmark Definitions** Each test case consists of a JavaScript code snippet that defines two arrays (`a1` and `a2`) and then attempts to concatenate them using one of the three methods. The `benchmark definition` specifies the exact implementation used in each test case: 1. **Concat**: `const result = array1.concat(array2)`. * This method uses the built-in `concat` function, which creates a new array by appending all elements from `array2` to `array1`. * Pros: Simple and straightforward. * Cons: Creates a new array object and copies all elements, which can be inefficient for large arrays. 2. **Spread**: `const result = [...array1, ...array2]`. * This method uses the spread operator (`...`) to create a new array by spreading all elements from `array2` onto `array1`. * Pros: More efficient than `concat`, as it avoids creating a new object and copies only the necessary elements. * Cons: Requires modern JavaScript versions (ES6+) and may not work in older browsers or environments. 3. **Push**: `a1.push(...array2)`. * This method uses the `push` function to add all elements from `array2` onto `array1`. * Pros: Efficient, as it modifies the existing array object and avoids creating a new one. * Cons: May not be suitable for older browsers or environments that don't support spread syntax. **Library Usage** None of the test cases use any external libraries. They rely solely on built-in JavaScript features to compare the performance of different concatenation methods. **Special JS Features/Syntax** The tests use modern JavaScript features, including: * Spread operator (`...`): Only used in the "spread" test case. * Modern arrow functions (not explicitly mentioned but implied by the `const` syntax). * Object literals and array literals (used for defining arrays). **Other Considerations** When evaluating the performance of these concatenation methods, consider factors such as: * **Memory allocation**: How much memory is required to create a new array or object? This can impact performance in scenarios where memory is limited. * **Copy-on-write vs. reference semantics**: The spread operator uses reference semantics, which means that it doesn't copy the elements; instead, it creates a new reference to the original elements. This can be more efficient than copy-on-write approaches used by `concat` and `push`. * **Browser support**: Make sure to test in different browsers and environments to ensure compatibility. **Alternatives** If you're looking for alternatives or variations on these concatenation methods, consider: * Using other spread operators, like `Array.prototype.push.apply()`, which can be more efficient but may not work with older browsers. * Utilizing libraries like Lodash or Ramda, which provide optimized array manipulation functions that might outperform the built-in `concat` and `push`. * Implementing custom concatenation algorithms using bitwise operations or other low-level techniques. Keep in mind that these alternatives may come with trade-offs in terms of complexity, compatibility, or performance.
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