Can ‘=’ be used to set one object property given a different unique key:value?

If I know an object exists in an array with a unique key:value pair do I have use .find() to get the object or is there a way that doesn’t require iteration?

Given:

const testObj = [
{id: '001', first: 'fThing1', other: [{id: '001.1'}, {id: '001.2'}], arr: ['a1', 'b1', 'c1'] },
{id: '002', first: 'fThing2', other: [{id: '002.1'}, {id: '002.2'}], arr: ['a2', 'b2', 'c2'] },
{id: '003', first: 'fThing3', other: [{id: '003.1'}, {id: '003.2'}], arr: ['a3', 'b3', 'c3'] }
]

Is there a notation to do:

testObj.id['001'](some notation)first = 'something'

Or do I have to do:

temp = testObj.find(to => to.id === '001')
temp.first = 'something'

Answer

To directly answer your question…

Is there a notation to do

The answer is “no”.

If your elements have unique IDs, considering collecting them into a Map keyed by id if you need that sort of access…

const testObj = [{"id":"001","first":"fThing1","other":[{"id":"001.1"},{"id":"001.2"}],"arr":["a1","b1","c1"]},{"id":"002","first":"fThing2","other":[{"id":"002.1"},{"id":"002.2"}],"arr":["a2","b2","c2"]},{"id":"003","first":"fThing3","other":[{"id":"003.1"},{"id":"003.2"}],"arr":["a3","b3","c3"]}]

const idMap = new Map(testObj.map(o => [o.id, o]))

// word of warning, this will error if the ID doesn't exist
idMap.get("001").first = "something"

console.log(testObj[0])
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Because the object references in testObj and the Map are the same, any changes to one will be reflected in the other.