Run results for: Different ways of creating a Dictionary

- Array.map with Object.fromEntries - Array.map with Object.fromEntries with new Map - Reduce with new Object (`{}`) (reusing object) - Reduce with new Object (`{}`) (creating temporary objects) - Reduce with new Map (reusing map)

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Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:105.0) Gecko/20100101 Firefox/105.0

Browser: Firefox 105

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Array.map with Object.fromEntries	3553.8 Ops/sec
Array.map with new Map	1170.9 Ops/sec
Reduce with new Object (`{}`) (reusing object)	6117.0 Ops/sec
Reduce with new Object (`{}`) (creating temporary objects)	0.3 Ops/sec
Reduce with new Map (reusing map)	1350.2 Ops/sec

Script Preparation code:

var ids = Array.from(Array(10000).keys())

var data = ids.map(item => ({ id: item, random: Math.random() }))

Tests:

Array.map with Object.fromEntries
// Create the dictionary // Using `Object.fromEntries` and `Array.map` const dictionary = Object.fromEntries( data.map((item) => [ // Key item.id, // Item item, ]) ); // Utilize it, to test the performance of the dictionary itself as well. ids.map((id) => dictionary[id]);
Array.map with new Map
// Create the dictionary // Using `new Map` and `Array.map` const dictionary = new Map( data.map((item) => [ // Key item.id, // Item item, ]) ); // Utilize it, to test the performance of the dictionary itself as well. ids.map((id) => dictionary.get(id));
Reduce with new Object (`{}`) (reusing object)
// Create the dictionary // Using `Array.reduce` with `new Object()` // And reusing the object const dictionary = data.reduce((obj, item) => { obj[item.id] = item; return obj; }, {}); // Utilize it, to test the performance of the dictionary itself as well. ids.map((id) => dictionary[id]);
Reduce with new Object (`{}`) (creating temporary objects)
// Create the dictionary // Using `Array.reduce` with `new Object()` // And NOT reusing the object const dictionary = data.reduce((obj, item) => { return { ...obj, [item.id]: item }; }, {}); // Utilize it, to test the performance of the dictionary itself as well. ids.map((id) => dictionary[id]);
Reduce with new Map (reusing map)
// Create the dictionary // Using `Array.reduce` with `new Map` // And reusing the map const dictionary = data.reduce((map, item) => { map.set(item.id, item); return map; }, new Map()); // Utilize it, to test the performance of the dictionary itself as well. ids.map((id) => dictionary.get(id));

Run results for: Different ways of creating a Dictionary

- Array.map with Object.fromEntries - Array.map with Object.fromEntries with new Map - Reduce with new Object (`{}`) (reusing object) - Reduce with new Object (`{}`) (creating temporary objects) - Reduce with new Map (reusing map)

Array.map with Object.fromEntries

Array.map with new Map

Reduce with new Object (`{}`) (reusing object)

Reduce with new Object (`{}`) (creating temporary objects)

Reduce with new Map (reusing map)