Javascript - find highest value in an object of arrays of objects

Question

I have an object containing arrays of objects. I'm trying to find the highest value of an object property, 'sortOrder' without manually iterating through the arrays and objects.

So my variable looks like this following:

const myObj = {
 people: [
   0: {firstname: 'Dave', lastName: 'Jones', sortOrder: 22},
   1: {firstname: 'Jane', lastName: 'Smith', sortOrder: 11}
 ],
 otherPeople: [
   0: {firstname: 'Jen', lastName: 'SomeLastName', sortOrder: 33},
   1: {firstname: 'ExampleFirstName', lastName: 'ExampleLastName', sortOrder: 12}
 ]
};

So I'd be trying to iterate through this to eventually find, in this case, the highest sortOrder of 33. Not necessarily the array index or the object containing it, just the number.

Thanks

Are you trying to have the people and otherPeople sorted by the sortOrder descending? — Branchverse
– Branchverse, Commented Dec 7, 2021 at 21:23
if you have them already sorted, then just return sortOrder of the first element in the array it will be the highest — Branchverse
– Branchverse, Commented Dec 7, 2021 at 21:30

Majed Badawi · Accepted Answer · 2021-12-07 21:37:49Z

1

Using Object#values get the list of arrays
Using Array#flat, convert the 2d array into one
Using Array#reduce, iterate over this list while updating a max

const myObj = {
  people: [ {firstname: 'Dave', lastName: 'Jones', sortOrder: 22}, {firstname: 'Jane', lastName: 'Smith', sortOrder: 11} ],
  otherPeople: [ {firstname: 'Jen', lastName: 'SomeLastName', sortOrder: 33}, {firstname: 'ExampleFirstName', lastName: 'ExampleLastName', sortOrder: 12} ]
};

const maxSortOrder = 
  Object.values(myObj)
  .flat()
  .reduce((max, { sortOrder = 0 }) => sortOrder > max ? sortOrder : max, 0);

console.log(maxSortOrder);

edited Dec 7, 2021 at 21:37

answered Dec 7, 2021 at 21:23

Majed Badawi

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Comments

Daniel Beck · Accepted Answer · 2021-12-07 21:29:40Z

1

(I had to slightly correct your input data: arrays don't include the index number as you're showing.)

Easiest to combine the two arrays in the object into one list and then use reduce to find the maximum:

const myObj = {
  people: [
    {
      firstname: 'Dave',
      lastName: 'Jones',
      sortOrder: 22
    },
    {
      firstname: 'Jane',
      lastName: 'Smith',
      sortOrder: 11
    }
  ],
  otherPeople: [
    {
      firstname: 'Jen',
      lastName: 'SomeLastName',
      sortOrder: 33
    },
    {
      firstname: 'ExampleFirstName',
      lastName: 'ExampleLastName',
      sortOrder: 12
    }
  ]
};


let allPeople = [...myObj.people, ...myObj.otherPeople];

let max = allPeople.reduce((maxSort, person) => {
  return Math.max(maxSort, person.sortOrder)
}, 0));

console.log(max)

answered Dec 7, 2021 at 21:29

Daniel Beck

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1 Comment

TCooper Over a year ago

+1 for taking the clean your data/(re-)organize your data then it's simple approach. I too often fall victim to writing overly complex code to handle poor data choices, instead of fixing the root problem. (not that OP made a poor data choice in sample here, but data manipulation is a good solution for this problem anyway)

Branchverse · Accepted Answer · 2021-12-07 21:43:05Z

1

You can order them by the highest sortOrder and then take the higher of the highest elements in each array:

const myObj = {
  people: [{
      firstname: 'Dave',
      lastName: 'Jones',
      sortOrder: 22
    },
    {
      firstname: 'Jane',
      lastName: 'Smith',
      sortOrder: 11
    }
  ],
  otherPeople: [{
      firstname: 'Jen',
      lastName: 'SomeLastName',
      sortOrder: 33
    },
    {
      firstname: 'ExampleFirstName',
      lastName: 'ExampleLastName',
      sortOrder: 12
    }
  ]
};
Object.values(myObj).forEach(peopleArray => {
  peopleArray.sort((a, b) => b.sortOrder - a.sortOrder)
})
let maxValue = Math.max(myObj.people[0].sortOrder, myObj.otherPeople[0].sortOrder)
console.log(maxValue)

edited Dec 7, 2021 at 21:43

answered Dec 7, 2021 at 21:35

Branchverse

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2 Comments

TCooper Over a year ago

"If you have the array elements already sorted by sortOrder" I think your answer could be better if you take out the conditional and include the sorting as a necessary portion of the answer. As asked it isn't conditional / that's not extra information to the solution; its a distinct portion of it.

Branchverse Over a year ago

alright thank you for the tip

Takilleur · Accepted Answer · 2021-12-07 22:58:06Z

0

const myObj = {
people: [
    {firstname: 'Dave', lastName: 'Jones', sortOrder: 22},
    {firstname: 'Jane', lastName: 'Smith', sortOrder: 11}
],
otherPeople: [
    {firstname: 'Jen', lastName: 'SomeLastName', sortOrder: 33},
    {firstname: 'ExampleFirstName', lastName: 'ExampleLastName', sortOrder: 12}
]};

let maxSortOrder = 0;
for (const value of Object.values(myObj)) {
    maxSortOrder = value.reduce((acc, { sortOrder }) => sortOrder > acc ? sortOrder : acc, maxSortOrder);
};

console.log(maxSortOrder); //33

answered Dec 7, 2021 at 22:58

Takilleur

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