finding duplicates in array of objects javascript

Question

I have an array of objects that looks like the following:

            {value: 20, color: 'F88C00'},
            {value: 40, color: 'D8605F'},
            {value: 20, color: '72C380'},
            {value: 20, color: '2C7282'},
            {value: 20, color: '72C380'}

I want to use javascript/jquery to loop through them to check if there are any duplicates in the color column, and if there are duplicates, here '72C380' occurs twice. Then there should be only one entry but their values should be summed.

Desired Output:

            {value: 20, color: 'F88C00'},
            {value: 40, color: 'D8605F'},
            **{value: 40, color: '72C380'},**
            {value: 20, color: '2C7282'}

I know how to do that in python, but not JS

Do you want to delete it? – Mohammad Kermani Jun 18 '14 at 05:32 — Mohammad Kermani, Jun 18 '14 at 05:32
I want to delete the duplicate ones but add upp the values – Rahul Bhatia Jun 18 '14 at 05:39 — Rahul Bhatia, Jun 18 '14 at 05:39

score 8 · Answer 1 · answered Jun 18 '14 at 05:36

You can use a temp map like this

var array = [{
    value: 20,
    color: 'F88C00'
}, {
    value: 40,
    color: 'D8605F'
}, {
    value: 20,
    color: '72C380'
}, {
    value: 20,
    color: '2C7282'
}, {
    value: 20,
    color: '72C380'
}];

var op = [],
    map = {}, it, item;
for (var i = 0; i < array.length; i++) {
    it = array[i];
    item = map[it.color];
    if (item) {
        item.value += it.value;
    } else {
        map[it.color] = item = {
            value: it.value,
            color: it.color
        };
        op.push(item);
    }
}
console.log(op)

Demo: Fiddle

score 0 · Answer 2 · answered Jun 18 '14 at 06:26

console it ...

var collection = [{value: 20, color: 'F88C00'},
            {value: 40, color: 'D8605F'},
            {value: 20, color: '72C380'},
            {value: 20, color: '2C7282'},
            {value: 20, color: '72C380'}];


var colors = [];
var result = collection;
$.each(result, function(i, item){ 
  if(colors.indexOf(item.color)!= -1){ 
      $.each(result,function(f, find){
        if(find.color == item.color){
          result[f].value += item.value;
        }
      })
      delete result[i];
  }else{
     colors.push(item.color);  
  } 
})
var colors = [];
console.log(result);

finding duplicates in array of objects javascript

2 Answers2

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