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JavaScript spread operator vs Object.a
(version: 0)
Comparing performance of:
Using the spread operator vs Using Object.assign
Created:
4 years ago
by:
Guest
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Tests:
Using the spread operator
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...{}, ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = Object.assign({},firstObject, secondObject);
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Suite status:
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Test case name
Result
Using the spread operator
Using Object.assign
Fastest:
N/A
Slowest:
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the benchmark and explain what's being tested. **Benchmark Test Case** The test case is comparing two ways to merge objects in JavaScript: using the spread operator (`...`) and `Object.assign()`. **Spread Operator (Using the Spread Operator)** The spread operator is a feature introduced in ECMAScript 2018 (ES9). It allows you to expand an object into multiple instances, making it easier to create new objects with initial values from existing ones. In this test case, the script creates two objects: `firstObject` and `secondObject`. Then, it uses the spread operator to merge these objects into a single object, `finalObject`, which is created using the syntax `{ ... {}, ...firstObject, ...secondObject }`. **Object.assign()** `Object.assign()` is a method that copies the properties of one or more source objects to a target object. In this test case, the script creates two objects: `firstObject` and `secondObject`. Then, it uses `Object.assign()` to merge these objects into a single object, `finalObject`, which is created using the syntax `Object.assign({}, firstObject, secondObject)`. **Comparison** The benchmark is comparing the performance of both approaches: * Using the spread operator: `{ ... {}, ...firstObject, ...secondObject }` * Using `Object.assign()` with an initial empty object: `Object.assign({}, firstObject, secondObject)` **Pros and Cons** **Spread Operator** Pros: * Easier to read and write, especially for more complex merges. * Can be used in a more declarative way. Cons: * May have performance overhead due to the creation of intermediate objects. * Not supported in older browsers or Node.js versions. **Object.assign()** Pros: * Generally faster than the spread operator due to its optimized implementation. * Widely supported across browsers and Node.js versions. Cons: * Can be less readable, especially for more complex merges. * Requires the initial empty object to be created explicitly. **Other Considerations** Both approaches have their trade-offs. The spread operator provides a more declarative and concise way of merging objects, but may introduce performance overhead. `Object.assign()` is generally faster, but can be less readable and require more manual effort to handle edge cases. It's worth noting that the benchmark results provided in this case show that the spread operator has slightly better performance than `Object.assign()`, but these results may vary depending on specific use cases and browser versions. **Alternatives** If you're looking for alternative approaches, consider: * Using a library like Lodash or Ramda, which provide more functional programming-style merging functions. * Using a different merge strategy, such as using `JSON.parse(JSON.stringify())` to create a deep copy of one object into another.
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