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Javascript – filtering an object-array based on another object-array (orderly)

here is my data:

arrayA= [{"studentID":1,"Type":"A"},{"studentID":2,"Type":"B"},{"studentID":3,"Type":"C"},{"studentID":4,"Type":"A"}]
filteredArrayOrderlyOn = [{"studentID":1},{"Type":"A"}] (depending on the order the user selects the filters)

Output should be 
arrayA = [{"studentID":1,"Type":"A"}]

or if the filteredArrayOrderlyOn array changes because user has control on this selection.

filteredArrayOrderlyOn  = [{"Type":"B"},{"studentID":1}] then output should be nothing []
Or if  
fillteredArrayOrderlyOn  = [{"Type":"A"}] 
then output should be
arrayA= [{"studentID":1,"Type":"A"},{"studentID":4,"Type":"A"}]

So i would like to filter ArrayA, in the correct order, meaning that in filteredArrayOrderly first the filter should be studentID=1 and then Type which is A.

i have been trying without any luck


newArray = arrayA.filter(function (item) {
    return Object.keys(elem) === Object.keys(item);
  });
})

or using lodash

 newArray = _.filter(arrayA, function (elem) {
  //     return elem.Type=== filteredArrayOrderlyOn.Type ||  elem.studentID=== filteredArrayOrderlyOn.studentID
  //   });

but getting too many repetitions
thakns guys

Tags:

2

Answers


  1. 0

    To filter arrayA based on the filters in filteredArrayOrderlyOn in the correct order, you can iterate over the filters and apply them sequentially to the array.

    let arrayA = [
  { "studentID": 1, "Type": "A" },
  { "studentID": 2, "Type": "B" },
  { "studentID": 3, "Type": "C" },
  { "studentID": 4, "Type": "A" }
];

let filteredArrayOrderlyOn = [
  { "studentID": 1 },
  { "Type": "A" }
];

let filteredArray = arrayA;

filteredArrayOrderlyOn.forEach(filter => {
  const key = Object.keys(filter)[0];
  const value = filter[key];
  filteredArray = filteredArray.filter(item => item[key] === value);
});

console.log(filteredArray);

    In this filteredArrayOrderlyOn is iterated over, and for each filter, the filteredArray is further filtered based on the key-value pair in the filter object. This ensures that the filters are applied in the correct order.

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  2. 0

    You can use Array#every() to match any number of keys in the filters:

    let arrayA = [
  { "studentID": 1, "Type": "A" },
  { "studentID": 2, "Type": "B" },
  { "studentID": 3, "Type": "C" },
  { "studentID": 4, "Type": "A" }
];

let filteredArrayOrderlyOn = [
  { "studentID": 1 },
  { "Type": "A" }
];

const result = arrayA.filter(item => 
  filteredArrayOrderlyOn.every(filter => Object.keys(filter).every(key => item[key] === filter[key]))
);

console.log(result);
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