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JavaScript spread operator vs Object.assign performanceoa sdhp hsh [AODSAMDF HAj mQ;D HKDAN DJH Q'djdn jwqncs;djfq'ocj c[qiw nc;hwe'pojca[qie;wfd
(version: 0)
Comparing performance of:
Using the spread operator vs Using Object.assign
Created:
5 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);
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
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Test case name
Result
Using the spread operator
Using Object.assign
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down what is being tested in this benchmark. **What is being tested?** Two different approaches are being compared: using the JavaScript spread operator (`...`) and `Object.assign()` to merge two objects into a new object. **Options compared:** 1. **Using the spread operator (`...`)**: This approach creates a new object by spreading the properties of one or more source objects into a new object. 2. **Using `Object.assign()`**: This approach creates a new object by copying the properties from one or more source objects into an existing object. **Pros and Cons of each approach:** 1. **Using the spread operator (`...`)**: * Pros: + More concise and expressive code + Creates a new object, which can be beneficial for immutability and predictable behavior * Cons: + May incur overhead due to stringification and deserialization of the spread expression + Can lead to performance issues if not used carefully (e.g., with very large objects) 2. **Using `Object.assign()`**: * Pros: + More predictable and controlled behavior, as it explicitly copies properties from source objects + Can be faster for small objects or when working with specific property sets * Cons: + Less concise and expressive code + May lead to mutable side effects if not used carefully **Library and purpose:** None of the benchmark tests use any external libraries. The `Object.assign()` method is a built-in JavaScript function, while the spread operator (`...`) was introduced in ECMAScript 2015 (ES6) as a feature addition. **Special JS feature or syntax:** The spread operator (`...`), also known as destructuring assignment, is a new way of creating objects. It allows you to extract properties from an object and assign them to variables or other objects. This feature was introduced in ECMAScript 2015 (ES6) as a way to simplify object creation and manipulation. **Other alternatives:** If the spread operator (`...`) or `Object.assign()` are not suitable for your use case, you can consider using other approaches: 1. **Using `Array.prototype.reduce()`**: You can use `reduce()` to merge two objects by creating an initial value and then iteratively adding properties from each source object. 2. **Using `JSON.parse(JSON.stringify())`**: This approach serializes both objects as JSON strings, merges them, and then parses the resulting string back into a JavaScript object. 3. **Using a custom function**: You can write your own function to merge two objects using a specific algorithm or data structure. However, these alternatives may not offer better performance or predictability than the spread operator (`...`) or `Object.assign()`, depending on your specific use case and requirements.
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