Steps to allocate the asset in case of null value

Question

Steps to allocate the asset in case of null value

I encountered a situation where I had an array of objects with duplicate ids. Each object linked to the id contains two properties: A and B. In the first index of the array, property A has a value while property B is null. Conversely, in the second index, property A is null and property B has a value. The goal is to merge these two indexes based on the same id. However, the output currently does not display values for both properties A and B - one of them remains null.

Array

{
  id: 123,
  A: “value A1”,
  B: null
},
{
  id: 123,
  A: null,
  B: “value b”
},
{
  id: 123,
  A: “value A2”,
  B: null
},
{
  id: 456,
  A: "a2 value",
  B: "b2 value"
}

Code

var output = _.groupBy(arr, function(o){
   return o.id;
})

Output

{
  id: 123,
  A: [“value A1”, “value A2”],
  B: null
},
{
  id: 456,
  A: ["a2 value"],
  B: "b2 value"
}

Expected

{
  id: 123,
  A: [“value A1”, “value A2”],
  B: “value b”
},
{
  id: 456,
  A: ["a2 value"],
  B: "b2 value"
}

javascript arrays lodash

Answer 1

Answer №1

Here is a way to achieve this without using underscore and loadash:

var items = [
    {
        id: 123,
        A: "value A1",
        B: null
    },
    {
        id: 123,
        A: null,
        B: "value b"
    },
    {
        id: 123,
        A: "value A2",
        B: null
    },
    {
        id: 456,
        A: "a2 value",
        B: "b2 value"
    }    
];

var updatedItems = items.reduce((accumulator, currentItem) => {
    var existingItem = accumulator.find(item => item.id === currentItem.id);
    if (existingItem) {
        currentItem.A && (existingItem.A.push(currentItem.A));
        existingItem.B = existingItem.B || currentItem.B;
    } else {
        currentItem.A = currentItem.A ? [currentItem.A] : [];
        accumulator.push(currentItem);
    }
    return accumulator;
}, []);

console.log(updatedItems);

Answer 2

Here is a way to achieve this without using underscore and loadash:

var items = [
    {
        id: 123,
        A: "value A1",
        B: null
    },
    {
        id: 123,
        A: null,
        B: "value b"
    },
    {
        id: 123,
        A: "value A2",
        B: null
    },
    {
        id: 456,
        A: "a2 value",
        B: "b2 value"
    }    
];

var updatedItems = items.reduce((accumulator, currentItem) => {
    var existingItem = accumulator.find(item => item.id === currentItem.id);
    if (existingItem) {
        currentItem.A && (existingItem.A.push(currentItem.A));
        existingItem.B = existingItem.B || currentItem.B;
    } else {
        currentItem.A = currentItem.A ? [currentItem.A] : [];
        accumulator.push(currentItem);
    }
    return accumulator;
}, []);

console.log(updatedItems);

Answer 3

Answer №2

Here's an example using plain JavaScript without the need for underscore or lodash.

var data = [{
    id: 123,
    A: "some value",
    B: null
  },
  {
    id: 123,
    A: null,
    B: "b value"
  },
  {
    id: 456,
    A: "a2 value",
    B: "b2 value"
  }
];

var outputObject = {},
  outputArray = [];

data.forEach(function(obj) {

  if (!outputObject[obj.id]) {
    outputObject[obj.id] = obj;
  } else {
    if (obj.B !== null) {
      outputObject[obj.id].B = obj.B;
    }
    if (obj.A !== null) {
      outputObject[obj.id].A = obj.A;
    }
  }

});

//Convert to an array
Object.keys(outputObject).forEach(function(key) {
  outputArray.push(outputObject[key]);
});

console.log(outputArray);

Answer 4

Here's an example using plain JavaScript without the need for underscore or lodash.

var data = [{
    id: 123,
    A: "some value",
    B: null
  },
  {
    id: 123,
    A: null,
    B: "b value"
  },
  {
    id: 456,
    A: "a2 value",
    B: "b2 value"
  }
];

var outputObject = {},
  outputArray = [];

data.forEach(function(obj) {

  if (!outputObject[obj.id]) {
    outputObject[obj.id] = obj;
  } else {
    if (obj.B !== null) {
      outputObject[obj.id].B = obj.B;
    }
    if (obj.A !== null) {
      outputObject[obj.id].A = obj.A;
    }
  }

});

//Convert to an array
Object.keys(outputObject).forEach(function(key) {
  outputArray.push(outputObject[key]);
});

console.log(outputArray);

Steps to allocate the asset in case of null value

Answer №1

Answer №2

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