How to access the count of duplicates in javascript/typescript

Question

I have an array of data => this.allNodeSets. To this array, i find the duplicates. And now i want to find the count of duplicates. The only way to find the duplicate count is say => itemCount.ball

Dummy code -

var randomArray = ["ball", "ball", "tree", "ball", "tree", "bus", "car"];
var itemCount = {};

randomArray.forEach(function(value){
    if(value in itemCount) itemCount[value] = itemCount[value] + 1;
    else itemCount[value] = 1;
});

To find the count - do =>

 itemCount.ball

I am finding difficulty in finding this individual count like done above. My Code -

app.component.ts - Angular2+

callFunctionSingleSelectedResult(){

allNodeSets = [
 ["claimIntimationRequestBody", "claimIntimationRequestHeader"],
 ["claimIntimationRequestBody", "claimIntimationRequestHeader"],
 ["claimIntimationRequestBody", "claimIntimationRequestBody"],
["claimIntimationRequestBody", "claimIntimationRequestHeader"],
 ["claimIntimationRequestBody", "claimIntimationResponseBody"],
 ["claimIntimationRequestHeader", "claimIntimationRequestBody"],
 ["claimIntimationRequestHeader", "claimIntimationRequestHeader"],
 ["claimIntimationRequestHeader", "claimIntimationResponseBody"],

 ["claimIntimationRequestBody", "claimIntimationRequestHeader"],

 ["claimIntimationRequestBody", "claimIntimationResponseBody"],
 ["claimIntimationRequestHeader", "claimIntimationResponseBody"],
]


       var duplicateResult = this.findDuplicates(this.allNodeSets);

       console.log("inside duplicates, result= ", duplicateResult);



//------------[1] count duplicates


              var itemCount = {};

              duplicateResult.forEach(function (value) {
                if (value in itemCount)
                  itemCount[value] = itemCount[value] + 1;
                else itemCount[value] = 1;


              });

              console.log("duplicateResult, forEach = count = ", 
           itemCount)

              for (var i = 0; i < duplicateResult.length; i++) {

                console.log(" individual count = ", itemCount)
              }

}


 // finding Duplicates

  findDuplicates(arr) {
    var len = arr.length,
      out = [],
      counts = {};

    for (var i = 0; i < len; i++) {
      var item = arr[i];
      counts[item] = counts[item] >= 1 ? counts[item] + 1 : 1;
      if (counts[item] > 1) {
        out.push(item);
      }
    }

    return out;
  }

  // Function duplicate ends

Output -

 duplicateResult = 
    [ 
    ["claimIntimationRequestBody","claimIntimationRequestHeader"],
    ["claimIntimationRequestBody", "claimIntimationRequestHeader"], 
    ["claimIntimationRequestBody","claimIntimationRequestHeader"] ,
    ["claimIntimationRequestBody","claimIntimationResponseBody"],
    ["claimIntimationRequestHeader", "claimIntimationResponseBody"] , 
    ["claimIntimationRequestHeader" "claimIntimationResponseBody"] 
    ]



    duplicate count, counter = {["claimIntimationRequestBody","claimIntimationRequestHeader"]: 3, 

["claimIntimationRequestBody","claimIntimationRequestBody"]: 1, 

["claimIntimationRequestBody","claimIntimationResponseBody"]: 1}

I searched the entire web but there is no other working way where i am able to determine a code that gives the count in some other way. Please help in determining a way to fetch the node count or maybe over here is there a way to fetch the node count. I am unable to do so.

If i do this -

 for (var i = 0; i < duplicateResult.length; i++) {

                console.log(" individual count = ", itemCount.duplicateResult)
              }

I get error -

Property 'duplicateResult' does not exist on type '{}'.

Reference -

How to check if the elements in an array are repeated?

yes. I found out the duplicates before its count . I shall include it in my question — Techdive, Dec 04 '18 at 09:38
Eliminating duplicate arrays will not work the way you are trying right now, arrays are referenced by address so two arrays containing same elements will be different when compared for equality — Ashish Ranjan, Dec 04 '18 at 09:41
You want to find the count of strings or the counts of subarray, please clarify ? — Arvind, Dec 04 '18 at 09:42
You assign `duplicateResult` variable to the result of `findDuplicates` call and then, reassign it with new value. Why? — hindmost, Dec 04 '18 at 09:56
Nooo... actually it is just for reference. I display the output for the reference of xyz. Please see the first comment. It is the actual result that i get after findDuplicates — Techdive, Dec 04 '18 at 09:59
Sidenote: actually you already have duplicates count in `findDuplicates` so you just do the same work again. — hindmost, Dec 04 '18 at 10:21

score 0 · Answer 1 · answered Dec 04 '18 at 09:45

0

var randomArray = ["ball", "ball", "tree", "ball", "tree", "bus", "car"];
var counts = {};
randomArray.forEach(function(x) { counts[x] = (counts[x] || 0)+1; });
console.log(counts)

this is a working example ,I hope this will help

answered Dec 04 '18 at 09:45

siddharth shah

1,139
1
9
17

score 0 · Answer 2 · answered Dec 04 '18 at 10:57

 var input= [ 
            ["claimIntimationRequestBody","claimIntimationRequestHeader"],
            ["claimIntimationRequestBody", "claimIntimationRequestHeader"], 
            ["claimIntimationRequestBody","claimIntimationRequestHeader"] ,
            ["claimIntimationRequestBody","claimIntimationResponseBody"],
            ["claimIntimationRequestHeader", "claimIntimationResponseBody"] , 
            ["claimIntimationRequestHeader", "claimIntimationResponseBody"] 
        ];
        
        var output = {};
        
        input.forEach(item => {
            // key is combination of all values of subarray  
            let key = item.join("_");
            if(!output[key]) output[key] = 0;
            output[key] +=1;
          }
        )
        console.log(output)

How to access the count of duplicates in javascript/typescript

2 Answers2