CODEWITHSUNDEEP
javascriptarraysjavascript-objects
Dexygen
Dexygen

Reputation: 12561

How to determine if any arrays in an object has an entry

This is unlike most questions, which concern arrays of objects, not objects of arrays. I have a data structure such as the following, and I need to determine if any of the arrays contained by the object contain any values.

All I need is true/false if any of the arrays has at least one value. Please also consider effort in my (self-)answer.

let pendingAdditions = {
  hospitals: ['Silencio Hospital','St Judes'],
  licenses: ['poe-tic license'],
  medschools: []
}

Upvotes: 0

Views: 91

Answers (2)

Siva Kondapi Venkata
Siva Kondapi Venkata

Reputation: 11011

How about Object.values with flat and includes.

// Check if Object has value as arrays and atleast one value is there.
const hasAnyEntry = (items) => Object.values(items).flat().length > 0;

const pendingAdditions = {
  hospitals: ['Silencio Hospital','St Judes'],
  licenses: ['poe-tic license'],
  medschools: []
}
console.log(hasAnyEntry(pendingAdditions));
console.log(hasAnyEntry({}));


// Check if given entry is exist in Object value arrays
const hasEntry = (items, entry) => Object.values(items).flat().includes(entry);

console.log(hasEntry(pendingAdditions, 'St Judes'));
console.log(hasEntry(pendingAdditions, 'Blah'));

Upvotes: 2

Dexygen
Dexygen

Reputation: 12561

I found nothing upon googling, maybe that is because the answer is as simple as:

let somePendingAdditions = Object.values(pendingAdditions).some(arr => arr.length);

However there is an alternative solution which is probably not as performant but also has interesting pitfalls possibly worth noting:

somePendingAdditions = 
    Boolean(Array.prototype.concat.apply([], Object.values(pendingAdditions)).length);

The pitfall(s) have to do with passing the correct first argument to apply. Ordinarily this is done with {} or null, but in the first case {} will be an entry in the resulting array; in the case of passing null an error results.

Upvotes: 3

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