How to filter an array of objects by attribute

Question

I've got an array of objects as follows:

finalistsCollection = [
    { name: 'Ann' , sections: [{id: '132', name: 'someName'}, {id: '456', name: 'someName'}] },
    { name: 'Jack' , sections: [{id: '798', name: 'someName'}] },
    { name: 'Morgan', sections: [{id: '456', name: 'someName'}] },
    { name: 'Billy', sections: [{id: '132', name: 'someName'}, {id: '456', name: 'someName'}]}, 
    { name: 'Monica', sections: [{id: '798', name: 'someName'}] }
]

How to filter this array by id value? For now, I've made filtering if a sections array has only one object inside:

filter(directionId) {
     filteredCollection = this.finalistsCollection.filter((item) => item.sections[0].id === directionId
}

I've tried to use map() function after the filter, but it still returns the whole array.

Does this answer your question? [How to filter object array based on attributes?](https://stackoverflow.com/questions/2722159/how-to-filter-object-array-based-on-attributes) — HMD, Apr 13 '20 at 15:08

score 0 · Answer 1 · answered Apr 13 '20 at 14:49

This works:

let finalistsCollection = [
    { name: 'Ann' , sections: [{id: '132', name: 'someName'}, {id: '456', name: 'someName'}] },
    { name: 'Jack' , sections: [{id: '798', name: 'someName'}] },
    { name: 'Morgan', sections: [{id: '456', name: 'someName'}] },
    { name: 'Billy', sections: [{id: '132', name: 'someName'}, {id: '456', name: 'someName'}]}, 
    { name: 'Monica', sections: [{id: '798', name: 'someName'}] }
]

function filter(directionId) {
     let filteredCollection = finalistsCollection.filter((item) => {
       for (const section of item.sections) {
         if (section.id === directionId) {
           return true
         }
       }
       return false
     })
     console.log(filteredCollection)
}

filter('456')

score 0 · Answer 2 · answered Apr 13 '20 at 15:04

Hope this helps

let finalistsCollection = [
  { name: 'Ann' , sections: [{id: '132', name: 'someName'}, {id: '456', name: 'someName'}] },
  { name: 'Jack' , sections: [{id: '798', name: 'someName'}] },
  { name: 'Morgan', sections: [{id: '456', name: 'someName'}] },
  { name: 'Billy', sections: [{id: '132', name: 'someName'}, {id: '456', name: 'someName'}]}, 
  { name: 'Monica', sections: [{id: '798', name: 'someName'}] }
]

function filter(directionId) {
  return finalistsCollection.filter(item =>
    item.sections.some(x => x.id === directionId)
  );
}

console.log(filter('456'));

Nilanka Manoj · Accepted Answer · 2020-04-13T14:56:51.037

-1

You can use a small trick here as the condition:

sections.map(section=>section.id).includes(directionId)

    finalistsCollection = [
        { name: 'Ann' , sections: [{id: '132', name: 'someName'}, {id: '456', name: 'someName'}] },
        { name: 'Jack' , sections: [{id: '798', name: 'someName'}] },
        { name: 'Morgan', sections: [{id: '456', name: 'someName'}] },
        { name: 'Billy', sections: [{id: '132', name: 'someName'}, {id: '456', name: 'someName'}]}, 
        { name: 'Monica', sections: [{id: '798', name: 'someName'}] }
    ]



    function filter(directionId) {
         return finalistsCollection.filter((item) =>
             item.sections.map(section=>section.id).includes(directionId))
    }
    
    console.log(filter('798'))
    console.log(filter('456'))
    console.log(filter('112'))

edited Apr 13 '20 at 14:56

answered Apr 13 '20 at 14:46

Nilanka Manoj

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Try it with `filter('456')`. – twharmon Apr 13 '20 at 14:50
`filter('456')` should return an array with 3 items. – twharmon Apr 13 '20 at 14:54
sorry for that. I refined answer – Nilanka Manoj Apr 13 '20 at 14:57

How to filter an array of objects by attribute

3 Answers3