CODEWITHSUNDEEP
javascriptarrays
Jan
Jan

Reputation: 145

How to get length of sub items in array

I want to get the total length number of items under arraycompany for example in below example it should be 5, do you have an idea how to do it in java script. thanks

this is my json:

var json ={
        "market": [
            {
                "company": [
                    {
                        "name": "A"
                    },
                    {
                        "name": "B"
                    },
                    {
                        "name": "C"
                    }
                ]
            },
            {
                "company": [
                    {
                        "name": "D"
                    },
                    {
                        "name": "E"
                    }
                ]
            }
        ]
    }

Upvotes: 1

Views: 770

Answers (5)

Yosvel Quintero
Yosvel Quintero

Reputation: 19070

You can use Array.prototype.reduce() to get the result

Code:

const json = {
  "market": [{
      "company": [{
          "name": "A"
        },
        {
          "name": "B"
        },
        {
          "name": "C"
        }
      ]
    },
    {
      "company": [{
          "name": "D"
        },
        {
          "name": "E"
        }
      ]
    }
  ]
};

const result = json.market.reduce((a, c) => a + c.company.length, 0);

console.log(result);

Upvotes: 0

Tyrannas
Tyrannas

Reputation: 4593

I'm also posting here a solution using lodash, a bit more complicated, but generic. Which means it's gonna count the total elements of every property: 

const data = {
  market: [
    { company: [1, 2, 3], address: [1, 2, 4], test: [6,7]},
    { company: [4, 5, 6], address: [3, 4], bonus: [9] }
  ]
};

// get the length of every array (this can actually be done without lodash with Object.keys(obj).forEach...)
temp = data.market.map(obj => _.mapValues(obj, o => o.length));

counter = {}
temp.forEach(arr => Object.keys(arr).forEach(el => (counter[el] = (counter[el] || 0) + arr[el])))

// counter = { company: 6, address: 5, test: 2, bonus: 1 }

Upvotes: 0

Negi Rox
Negi Rox

Reputation: 3922

this code may be helpful.

var totallength=0;
json.market.reduce(function(i,o){totallength+=o.company.length;},0);
console.log(totallength)

Upvotes: 0

nico
nico

Reputation: 654

json.market.reduce((acc, market) => acc + market.company.length, 0)

Upvotes: 1

brk
brk

Reputation: 50316

Use reduce function and update the value of the accumulator

var json = {
  "market": [{
      "company": [{
          "name": "A"
        },
        {
          "name": "B"
        },
        {
          "name": "C"
        }
      ]
    },
    {
      "company": [{
          "name": "D"
        },
        {
          "name": "E"
        }
      ]
    }
  ]
}

var x = json.market.reduce(function(acc, curr) {
   // acc mean the accumulator, 0 was passed as the first value
  acc += curr.company.length; 
  return acc;
}, 0) // 0 is the initial value
console.log(x)

Upvotes: 0

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