CODEWITHSUNDEEP
javascriptecmascript-6
Soumya Behera
Soumya Behera

Reputation: 2512

How to filter array of array objects?

Trying to filter array of array objects. when variable matches with array of object value of dropDownOne key 'filterValue', then it will return dropDownTwo array,

 let testName = ‘ filterValue’

 var nestedArray =  [
      [
          {
              dropDownOne: {
                  key: "filterValue",
                  value: "test1"
              },
              dropDownTwo: [
                  {
                      key: "retrieveArrKey1",
                      value: "test123"
                  },
                  {
                      key: "retrieveArrKey2",
                      value: "test345"
                  }
              ]
          }
      ],

[
          {
              dropDownOne: {
                  key: "NoFilter",
                  value: "test2"
              },
              dropDownTwo: [
                  {
                      key: "dropDown2",
                      value: "test"
                  },
                  {
                      key: "dropDown3",
                      value: "test"
                  }
              ]
          }
      ]
    ]




  Output = 
    
     dropDownTwo:[
                      {
                          key: "retrieveArrKey1",
                          value: "test123"
                      },
                      {
                          key: "retrieveArrKey2",
                          value: "test345"
                      }
                  ]

Tried with this

 let filterObj = nestedArray.filter((arr => arr.filter(value => {
        if (value[0].dropDownOne.key === 'filterValue') {
          return arr[1];
        }
      }))

But did not get the correct result

Upvotes: 0

Views: 77

Answers (4)

Vladislav Kibenko
Vladislav Kibenko

Reputation: 185

Don't like other solutions due to too many array iterations. You could make a single run using reduce function which is a grandfather of many JS Array functions. It looks a bit worse than flat-filter-flat-..., but will probably work way faster due to much lower array iterations.

const testName = 'filterValue';
const nestedArray = [
  [{
    dropDownOne: {key: 'filterValue', value: 'test1'},
    dropDownTwo: [
      {key: 'retrieveArrKey1', value: 'test123'},
      {key: 'retrieveArrKey2', value: 'test345'},
    ],
  }],
  [{
    dropDownOne: {key: 'NoFilter', value: 'test2'},
    dropDownTwo: [
      {key: 'dropDown2', value: 'test'},
      {key: 'dropDown3', value: 'test'},
    ],
  }],
];

const result = nestedArray.reduce((acc, nestedItem) => {
  nestedItem.forEach(item => {
    if (item.dropDownOne.key === testName) {
      acc.push(item.dropDownTwo);
    }
  });
  return acc;
}, []);

console.log(result);

Upvotes: 1

Mohammed Swillam
Mohammed Swillam

Reputation: 9242

You could use both flat() to flatten the nestedArray, then use the find() method to find the object with a dropDownOne.key that matches the value of testName.

it should then return the dropDownTwo property of that object.

let result = nestedArray.flat().find(obj => obj.dropDownOne.key === testName);
let filterObj = result ? result.dropDownTwo : [];
    
console.log(filterObj);

a full running example:

let testName = 'filterValue';

var nestedArray = [
  [{
    dropDownOne: {
      key: "filterValue",
      value: "test1"
    },
    dropDownTwo: [{
        key: "retrieveArrKey1",
        value: "test123"
      },
      {
        key: "retrieveArrKey2",
        value: "test345"
      }
    ]
  }],

  [{
    dropDownOne: {
      key: "NoFilter",
      value: "test2"
    },
    dropDownTwo: [{
        key: "dropDown2",
        value: "test"
      },
      {
        key: "dropDown3",
        value: "test"
      }
    ]
  }]
]

let result = nestedArray.flat().find(obj => obj.dropDownOne.key === testName);
let filterObj = result ? result.dropDownTwo : [];
    
console.log(filterObj);

Upvotes: 1

Ali Sattarzadeh
Ali Sattarzadeh

Reputation: 3559

You can do it in this way :

nestedArray.filter(arr => arr.find(item=> item.dropDownOne.key === 'filterValue'))[0][0].dropDownTwo


var nestedArray =  [
      [
          {
              dropDownOne: {
                  key: "filterValue",
                  value: "test1"
              },
              dropDownTwo: [
                  {
                      key: "retrieveArrKey1",
                      value: "test123"
                  },
                  {
                      key: "retrieveArrKey2",
                      value: "test345"
                  }
              ]
          }
      ],

[
          {
              dropDownOne: {
                  key: "NoFilter",
                  value: "test2"
              },
              dropDownTwo: [
                  {
                      key: "dropDown2",
                      value: "test"
                  },
                  {
                      key: "dropDown3",
                      value: "test"
                  }
              ]
          }
      ]
    ]




const result = nestedArray.filter(arr => arr.find(item=> item.dropDownOne.key === 'filterValue'))[0][0].dropDownTwo


console.log(result)

Upvotes: 1

flyingfox
flyingfox

Reputation: 13506

We can use Array.flat() and Array.flatMap() combined with Array.filter() to do it

let result = nestedArray.flat().filter(e => e.dropDownOne.key === testName).flatMap(e => e.dropDownTwo)
console.log(result)


let testName = `filterValue`

 var nestedArray =  [
      [
          {
              dropDownOne: {
                  key: "filterValue",
                  value: "test1"
              },
              dropDownTwo: [
                  {
                      key: "retrieveArrKey1",
                      value: "test123"
                  },
                  {
                      key: "retrieveArrKey2",
                      value: "test345"
                  }
              ]
          }
      ],

[
          {
              dropDownOne: {
                  key: "NoFilter",
                  value: "test2"
              },
              dropDownTwo: [
                  {
                      key: "dropDown2",
                      value: "test"
                  },
                  {
                      key: "dropDown3",
                      value: "test"
                  }
              ]
          }
      ]
    ]
    
let result = nestedArray.flat().filter(e => e.dropDownOne.key === testName).flatMap(e => e.dropDownTwo)
console.log(result)

Upvotes: 2

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