Use filter on a a multi level object array?

Question

Say I have a list of medical objects, where I want to select all objects that have a category of "MEDICATION" and also have a "Trait", which is an array of Objects, for specifically the term "NEGATION". For example:

[ 
  { 
   Score: 0.9978850483894348,
   Text: 'prozac',
   Category: 'MEDICATION',
   Type: 'BRAND_NAME',
   Traits: [
    { 
      Name: "SIGN"
    },
    { 
      Name: "NEGATION"
    }
  ] 
},
{ 
  Text: "pulmonary embolism",
  Category: "MEDICAL_CONDITION",
  Type: "DX_NAME",
  Traits: [
   {
     Name: "DIAGNOSIS",
     Score: 0.9635574817657471
    } ]

Normally for a filter I could select all objects that are medications quite easily with:

Object.filter( obj => obj.Category === "MEDICATION" )

But how would I select all objects with Medication, and also Trait with object where Name === NEGATION?

The nested array throws me off.

Thank you!

Adrian Brand · Accepted Answer · 2018-12-17 23:27:38Z

3

You can still use a filter but use some on the sub array

Object.filter(obj => obj.Traits.some(t => t.Name === 'NEGATION'));

const values = [
  {
    Score: 0.9978850483894348,
    Text: 'prozac',
    Category: 'MEDICATION',
    Type: 'BRAND_NAME',
    Traits: [
      {
        Name: 'SIGN'
      },
      {
        Name: 'NEGATION'
      }
    ]
  },
  {
    Text: 'pulmonary embolism',
    Category: 'MEDICAL_CONDITION',
    Type: 'DX_NAME',
    Traits: [
      {
        Name: 'DIAGNOSIS',
        Score: 0.9635574817657471
      }
    ]
  }
].filter(obj => obj.Category === 'MEDICATION' && obj.Traits.some(t => t.Name === 'NEGATION'));

console.log(values);

edited Dec 17, 2018 at 23:27

answered Dec 17, 2018 at 23:19

Adrian Brand

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2 Comments

nem035 Over a year ago

Using some instead of find is probably more semantically correct

Adrian Brand Over a year ago

Changed to use some instead of find

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