Question 417338 in Javascript Question posted in
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Javascript – Filter a object based on another Array

I am trying to filter a object based on an another array.

data = {
  'TypeA': ['A1', 'A2', 'A3', 'A4'],
  'TypeB': ['B1', 'B2', 'B3', 'B4'],
  'TypeC': ['C1', 'C2', 'C3', 'C4'],
}

array = ['TypeA', 'TypeB']

I want to get a new array with the values of both ‘TypeA’ and ‘TypeB’ like [‘A1’, ‘A2’, ‘A3’, ‘A4’, ‘B1’, ‘B2’, ‘B3’, ‘B4’] and remove duplicates if any also.

so far i have tried,

tTmp_Arr = data.filter(tObj => array.includes(tObj))

Any help is much appreciated.

Thanks in advance.

Thanks,

Tags:

3

Answers


  1. 0

    You can’t use filter on objects. You can get the result by flatmapping and then filtering as:

    const data = {
  'TypeA': ['A1', 'A2', 'A3', 'A4'],
  'TypeB': ['B1', 'B2', 'B3', 'B4'],
  'TypeC': ['C1', 'C2', 'C3', 'C4'],
};

const array = ['TypeA', 'TypeB'];

const result = array
  .flatMap(key => data[key] || []) 
  .filter((item, index, self) => self.indexOf(item) === index);
  
console.log(result);
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  2. 0

    Here’s another working example using array.reduce() with a for..of loop:

    const data =
{
  'TypeA': ['A1', 'A2', 'A3', 'A4'],
  'TypeB': ['B1', 'B2', 'B3', 'B4'],
  'TypeC': ['C1', 'C2', 'C3', 'C4'],
  
  // EXTRA
  'TypeExtra':
  [
    'A1', 'B1', 'C1',
    'EXTRA VALUE',
  ]
};

const array = ['TypeA', 'TypeB', 'TypeExtra'];

const result = array.reduce
(
  ( result, index ) =>
  {
    for ( const item of data[index] )
    {
      if ( ! result.includes(item) )
      {
        result.push(item);
      }
    }
    
    return result;
  },
  []
);

console.log(result);
    .as-console-wrapper { min-height: 100%; }
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  3. 0

    Here example using only for..loops

    const data = {
    'TypeA': ['A1', 'A2', 'A3', 'A4'],
    'TypeB': ['B1', 'A1', 'B2', 'B3', 'B4', 'A2'],
    'TypeC': ['C1', 'C2', 'C3', 'C4'],
}

const checkDublicate = (array, val) => {
    let dublicate = false
    array.forEach((element) => {
        if (element === val) dublicate = true
    })
    return dublicate
}

const filterFunction = (dataTypes, data) => {
    const temp = []
    for (let i = 0; i < dataTypes.length; i++) {
        const dataBase = data[dataTypes[i]]
        dataBase.forEach(element => {
            const check = checkDublicate(temp, element)
            if (!check) temp.push(element)
        });
    }
    return temp
}

const dataTypes = ['TypeA', 'TypeB']
const array = filterFunction(dataTypes, data)
console.log(array)
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