Loop objects in Javascript array and count similar items

Question

I am trying to loop thru an array of objects and get a count of similar values for a particular key when certain conditions are met. I tried looping on one array (storage) first but then realized that conditions had to be dynamic. They are not now. I entered in HR and Food but would ideally like to make those variables. So I'm looping thru values in arrayC and cross checking against storage for those value. If I loop once (have only one value in arrayC), it works but more than that, it loops too many times and gives me incorrect output. Trying to get a count of all similar award properties as it correlates to data and service. Example, so all objects with data: "HR" and Service: "Food" would be combined to reflect: {data:HR, service:Food, DDR: 3}

Code:

var arrayC = ["DDM","DDR"]; 
        var storage =  [
        { data: 'CT', service: 'Food',award: 'DDM' },
        { data: 'HR', service: 'Food',award: 'DDM' },
        { data: 'HR', service: 'Food',award: 'DDR' },
        { data: 'HR', service: 'Food',award: 'DDR' },
        { data: 'HR', service: 'Food',award: 'DDR' }
        ];
    
    var array1=[];
    var arrayTest = [];
    var jk ={};
    
    function getIt () {
    arrayC.forEach(function(key,value){
     
      $.each(storage, function(k,x){
       // console.log(v.award);
        if(key==x.award&&x.data=="HR"&&x.service=="Food"){
          jk[x.award] = jk.hasOwnProperty(x.award) ? arrayTest.push(x.award) : arrayTest.push(x.award), 
          jk.data = x.data,
          jk.service = x.service
          
        } 
      }); //inside each  
    });
      //array1.push(jk); 
      return jk;
    }
    
    var newThing = getIt();
    console.log(newThing);

    //Output: 
    //Object {
     // data: "HR",
     // DDM: 1,
     // DDR: 4,
     // service: "Food"
    //}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

sorry, forgot to mention, I'm stuck using ECMAScript 5. it doesn't support => But I might be able to convert that. — JackSki
– JackSki, Commented Mar 19, 2020 at 21:01

xdeepakv · Accepted Answer · 2020-03-20 07:56:12Z

2

You can use reduce and data and service combination string as key to count.

var storage = [
    { data: 'CT', service: 'Food', award: 'DDM' },
    { data: 'HR', service: 'Food', award: 'DDM' },
    { data: 'HR', service: 'Food', award: 'DDR' },
    { data: 'HR', service: 'Food', award: 'DDR' },
    { data: 'HR', service: 'Food', award: 'DDR' }
];

var res = storage.reduce(function (x, cur) {
    let item = cur.data + cur.award
    if (!x[item]) x[item] = 0;
    x[item] = x[item] + 1
    return x
}, {})
var results = []

for (const key in res) {
    const count = res[key];
    const data = key.slice(0, 2)
    const service = key.slice(2)
    results.push({
        data: data,
        service: service,
        count: count
    })
}
console.log(results)

edited Mar 20, 2020 at 7:56

answered Mar 19, 2020 at 17:35

xdeepakv

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3 Comments

JackSki Over a year ago

Thanks, xdeep, sorry, forgot to mention, I'm stuck using ECMAScript 5. it doesn't support => But I might be able to convert that. I noticed it's just pulling the DDR.

JackSki Over a year ago

Thanks, xdeepakv, I have to mark this as more correct because it literally answers the question and provides a working example based on the end formatted JSON (ultimate goal) in my question

xdeepakv Over a year ago

Thanks buddy!! KEEP CODING?!!

Nina Scholz · Accepted Answer · 2020-03-19 21:08:30Z

1

You could build a nested object with the counts of wanted keys.

var storage =  [{ data: 'CT', service: 'Food',award: 'DDM' }, { data: 'HR', service: 'Food',award: 'DDM' }, { data: 'HR', service: 'Food',award: 'DDR' }, { data: 'HR', service: 'Food',award: 'DDR' }, { data: 'HR', service: 'Food',award: 'DDR' }],
    keys = ['data', 'service', 'award'],
    counts = storage.reduce(function (r, o) {
        var last = o[keys[keys.length - 1]],
            reference = keys
                .slice(0, -1)
                .reduce(function (q, k) { return q[o[k]] = q[o[k]] || {}; }, r);
        reference[last] = (reference[last] || 0) + 1;
        return r;
    }, {});

console.log(counts);

edited Mar 19, 2020 at 21:08

answered Mar 19, 2020 at 17:31

Nina Scholz

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6 Comments

JackSki Over a year ago

thanks, Nina, sorry, forgot to mention, I'm stuck using ECMAScript 5 but maybe i can convert this

Guerric P Over a year ago

Babel to the rescue!

JackSki Over a year ago

Funny you should say that. I did that but it didn't translate correctly. Only some items turned out in the output. Nevermind, codepen wasn't showing all of the results but they were there. Strange, I wonder why codepen wouldn't show the break out. Either way, thanks Nina

JackSki Over a year ago

The only issue I'm having now is that I lost my generic keys (service, etc). Trying to get this data into datatables, which wants keys

JackSki Over a year ago

Nina, is there a way to flatten this. From: { "CT": { "Food": { "DDM": 1 } }, TO: {"data": "CT","service": "Food", "DDM": 1}

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