Question

I have an array of objects as follows within my server side JS:

[
    {
        "Company": "IBM"
    },
    {
        "Person": "ACORD LOMA"
    },
    {
        "Company": "IBM"
    },
    {
        "Company": "MSFT"
    },
    {
        "Place": "New York"
    }
]

I need to iterate through this structure, detect any duplicates and then create a count of a duplicate is found along side each value.

Both of the values must match to qualify as a duplicate e.g. “Company”: “IBM” is not a match for “Company”: “MSFT”.

I have the options of changing the inbound array of objects if needed. I would like the output to be an object, but am really struggling to get this to work.

EDIT: Here is the code I have so far where processArray is the array as listed above.

var returnObj = {};

    for(var x=0; x < processArray.length; x++){

        //Check if we already have the array item as a key in the return obj
        returnObj[processArray[x]] = returnObj[processArray[x]] || processArray[x].toString();

        // Setup the count field
        returnObj[processArray[x]].count = returnObj[processArray[x]].count || 1;

        // Increment the count
        returnObj[processArray[x]].count = returnObj[processArray[x]].count + 1;

    }
    console.log('====================' + JSON.stringify(returnObj));

Answer 1

For example:

counter = {}

yourArray.forEach(function(obj) {
    var key = JSON.stringify(obj)
    counter[key] = (counter[key] || 0) + 1
})

Docs: Array.forEach, JSON.stringify.