如何按属性过滤对象数组

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.

Answer 1

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')

Answer 2

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'));

Answer 3

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'))