How to replace an object in an array in JavaScript with a one-liner?

Question

Given an array with some object:

let array = [
  { name: 'bob', score: 12 },
  { name: 'Joe', score: 20 },
  { name: 'Sue', score: 25 }
]

How can I replace Joe's object in the array with this new object in a single line:

let newScoreForJoe = { name: 'Joe', score: 21 }

I know that I can find the index of Joe's object in the array and then update it like so:

let joeIndex = array.findIndex(x => x.name === newScoreForJoe.name)
array[joeIndex] = newScoreForJoe;

But is there an elegant one-liner to achieve the same thing?

Well you could get rid of the joeIndex and just do array[array.findIndex(x => x.name === newScoreForJoe.name)] = newScoreForJoe; — bamtheboozle
– bamtheboozle, Commented May 19, 2017 at 9:03
I think there will be no better solution, the 'name' property has no special rule to find. — KAngel7
– KAngel7, Commented May 19, 2017 at 9:07
@DragoşPaulMarinescu this is the best one. If you add it as an answer I will accept — railsuser400
– railsuser400, Commented May 19, 2017 at 9:13

bamtheboozle · Accepted Answer · 2017-05-19 09:15:55Z

1

You can simply get rid of the joeIndex variable all together and just do:

array[array.findIndex(x => x.name === newScoreForJoe.name)] = newScoreForJoe;

answered May 19, 2017 at 9:15

bamtheboozle

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Comments

ShukiB · Accepted Answer · 2017-05-19 09:09:09Z

1

I'm sure how elegant this will be for you but since you are trying to returm an array with the same amuount of objects, i would do this:

The array:

let array = [
  { name: 'bob', score: 12 },
  { name: 'Joe', score: 20 },
  { name: 'Sue', score: 25 }
]

The object:

let newScoreForJoe = { name: 'Joe', score: 21 }

The replace line:

let joeIndex = array.map(x => x.name === newScoreForJoe.name ? newScoreForJoe : x)

answered May 19, 2017 at 9:09

ShukiB

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Comments

Rex Adrivan · Accepted Answer · 2017-05-19 09:09:19Z

0

You can try this answer. Just change the value of the object property.

array[1].score = 21;

answered May 19, 2017 at 9:09

Rex Adrivan

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1 Comment

railsuser400 Over a year ago

This doesn't answer the question.

Nina Scholz · Accepted Answer · 2017-05-19 09:15:56Z

0

You could use Array#some and assign the new object inside of the callback.

If no object is found, no assignment happens.

let array = [{ name: 'bob', score: 12 }, { name: 'Joe', score: 20 }, { name: 'Sue', score: 25 }],
    newScoreForJoe = { name: 'Joe',score: 21 };
    
array.some((a, i, aa) => (a.name === newScoreForJoe.name && (aa[i] = newScoreForJoe)));

console.log(array);

answered May 19, 2017 at 9:15

Nina Scholz

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