How to tally objects within an array of nested array objects based on a specific property using JavaScript

Question

How to tally objects within an array of nested array objects based on a specific property using JavaScript

My dataset looks like this:

var data = [
  {
    items: [
      {
        id: 123
      },
      {
        id: 234
      },
      {
        id: 123
      }
    ]
  }, {
    items: [
      {
        id: 123
      },
      {
        id: 234
      }
    ]
  }
]

I am looking to count the objects deeply nested in arrays within all data based on the 'id' property. e.g.

data.countObject('id',123) //return 3.

My data has approximately xx,000 items, what is the best solution for this? Thank you for your assistance (apologies for any errors in my English).

javascript arrays json object count

Answer 1

Answer №1

To achieve this task, you can utilize the functions reduce and forEach. Within the reduce callback, you have access to the items array by referencing curr.items, where acc and curr serve as parameters for the callback function. Additionally, you can employ curr.items.forEach to iterate through each object within the items array.

var data = [{
  items: [{
      id: 123
    },
    {
      id: 234
    },
    {
      id: 123
    }
  ]
}, {
  items: [{
      id: 123
    },
    {
      id: 234
    }
  ]
}];

function getCount(id) {

  return data.reduce(function(acc, curr) {
    curr.items.forEach(function(item) {
      item.id === id ? acc += 1 : acc += 0;
    })
    return acc;
  }, 0)
}

console.log(getCount(123))

Answer 2

To achieve this task, you can utilize the functions reduce and forEach. Within the reduce callback, you have access to the items array by referencing curr.items, where acc and curr serve as parameters for the callback function. Additionally, you can employ curr.items.forEach to iterate through each object within the items array.

var data = [{
  items: [{
      id: 123
    },
    {
      id: 234
    },
    {
      id: 123
    }
  ]
}, {
  items: [{
      id: 123
    },
    {
      id: 234
    }
  ]
}];

function getCount(id) {

  return data.reduce(function(acc, curr) {
    curr.items.forEach(function(item) {
      item.id === id ? acc += 1 : acc += 0;
    })
    return acc;
  }, 0)
}

console.log(getCount(123))

How to tally objects within an array of nested array objects based on a specific property using JavaScript

Answer №1

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