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Map Array.from vs Spread
(version: 0)
Comparing performance of:
Array.from vs Spread
Created:
4 years ago
by:
Guest
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Tests:
Array.from
var fooMap = new Map(); for(var i=0;i<100;i++) { fooMap.set(i, i+'v'); } var other = Array.from(fooMap.values());
Spread
var fooMap = new Map(); for(var i=0;i<100;i++) { fooMap.set(i, i+'v'); } var other = [...fooMap];
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Suite status:
<idle, ready to run>
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Test case name
Result
Array.from
Spread
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 the provided benchmark and explain what is being tested. **Benchmark Purpose** The test case compares two approaches to convert a Map object into an array: `Array.from()` and the spread operator (`...`). **Approaches Comparison** 1. **Array.from()**: This method creates a new, shallow-copied array from an iterable or an array-like object. In this case, it's used to create an array of values from a Map object. 2. **Spread Operator (`...`)**: The spread operator is used to expand an iterable (like an array) into individual elements. When applied to a Map object, it creates an array of key-value pairs. **Pros and Cons** * **Array.from()**: + Pros: More explicit, efficient, and reliable way to convert a Map to an array. + Cons: May not be as intuitive for developers who are new to JavaScript or haven't used `Array.from()` before. * **Spread Operator (`...`)**: + Pros: More concise and readable, especially when dealing with simple conversions. + Cons: Can lead to unexpected behavior if the Map's values are not enumerable (e.g., objects) or if the conversion is not trivial. In general, `Array.from()` is a safer choice, as it explicitly converts the values, while the spread operator may rely on internal iteration and may fail for certain types of data. **Library/Liberal** There is no explicit library mentioned in the benchmark definition. However, both approaches use built-in JavaScript methods (`Array.from()` and spread operator). **Special JS Features/Syntax** Neither approach uses special JavaScript features or syntax. They are standard, well-established methods in modern JavaScript. **Other Alternatives** Before `Array.from()` and the spread operator, developers used more manual methods to convert a Map object into an array, such as using the `reduce()` method or iterating over the values manually. These alternatives can be useful in specific scenarios, but they are often less efficient and less readable than the current approaches. Some older browsers may not support the spread operator, so if you need to support very old browsers (e.g., Internet Explorer 11), you may need to use `Array.from()` or another alternative method.
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