const firstObject = { sampleData: 'Hello world' }
const secondObject = { moreData: 'foo bar' }
const finalObject = {
firstObject,
secondObject
};
const firstObject = { sampleData: 'Hello world' }
const secondObject = { moreData: 'foo bar' }
const a1 = Object.entries(firstObject)
const a2 = Object.entries(secondObject)
const finalObject = Object.fromEntries(a1.concat(a2));
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
Using the spread operator | |
Using Object.assign |
Test name | Executions per second |
---|---|
Using the spread operator | 16637534.0 Ops/sec |
Using Object.assign | 5937061.5 Ops/sec |
Let's break down what's being tested in the provided JSON.
Benchmark Definition
The benchmark compares two approaches to merge two objects:
...
): This syntax allows you to expand an object into new key-value pairs, merging them with existing ones. In this case, const finalObject = {...firstObject, ...secondObject}
will create a new object with all keys from both firstObject
and secondObject
.Object.assign()
method: This method takes multiple source objects as arguments and merges their key-value pairs into a target object.Options being compared
The benchmark compares the performance of these two approaches for merging two objects:
...
)Object.assign()
methodPros and Cons
...
):Object.assign()
method:const finalObject = Object.assign({}, firstObject, secondObject)
); syntax might be less readable for some developers.Library/Utility
In this benchmark, there is no explicit library or utility mentioned. However, it's worth noting that Object.entries()
is a built-in method in JavaScript that returns an array of key-value pairs from an object.
Special JS feature/Syntax
There is no special JavaScript feature or syntax being tested here, as both approaches use standard JavaScript syntax.
Other alternatives
If the benchmark were to test other methods for merging objects, some alternative approaches might include:
JSON.parse(JSON.stringify())
(although this method can be slower and less efficient than other options).merge()
function.Keep in mind that the performance differences between these methods are likely to be relatively small, especially for most use cases. The choice of method often depends on readability, maintainability, and specific requirements of the project.