Counting Elements in an Array, Adding them to 2 Objects within an Array

Question

var arr = ['cat','cat','dog','penguin','chicken','chicken']

function orgAnimals(input)
   var obj = {};
   for (var i = 0 ; i < input.length; i++) {
      obj[input[i]] = obj[input[i]] || 0;
      obj[input[i]]++
   }
return obj;
}

So this gives me {cat:2, dog:1, penguin:1, chicken:2,}

I want to split the object up into 2 different objects and put it in an array so it looks like

[{cat:2, dog:1} {penguin:1, chicken:2 }]

I tried an if statement to make that work but it's not. if (input[i]==='cat'||'dog') still gives me the same output as before.

Any hints? Am I using the operator incorrectly?

if (input[i]==='cat'||'dog') will always be true.

Sebastian Simon
– Sebastian Simon

2016-10-10 18:24:30 +00:00
Commented Oct 10, 2016 at 18:24 — Sebastian Simon
– Sebastian Simon, Commented Oct 10, 2016 at 18:24

adeneo · Accepted Answer · 2016-10-10 18:29:23Z

Golf time, I suppose

var arr = ['cat','cat','dog','penguin','chicken','chicken']

function orgAnimals(input) {
    return input.reduce((a, b) => {
    	var i = ['cat','dog'].indexOf(b) === -1 ? 1 : 0;
      	return b in a[i] ? a[i][b]++ : a[i][b] = 1, a
    }, [{},{}]);
}

console.log( orgAnimals(arr) );

Same logic, but a little more readable, where you check if the iterated value is either cat or dog and insert into the array based on a condition

var arr = ['cat', 'cat', 'dog', 'penguin', 'chicken', 'chicken']

function orgAnimals(input) {
    var arr = [{}, {}];
    
    for (var i = 0; i < input.length; i++) {
    
        if ( input[i] === 'dog' || input[i] === 'cat') {
        	if ( input[i] in arr[0] ) {
            	arr[0][ input[i] ] = arr[0][ input[i] ] + 1;
            } else {
            	arr[0][ input[i] ] = 1;
            }
        } else {
        	if ( input[i] in arr[1] ) {
            	arr[1][ input[i] ] = arr[1][ input[i] ] + 1;
            } else {
            	arr[1][ input[i] ] = 1;
            }
        }
    }
    return arr;
}

console.log( orgAnimals(arr) )

raphael75 · Accepted Answer · 2016-10-12 17:17:00Z

0

You would want to create 2 separate objects and then combine them in your return statement. So something like this:

if ((input[i] == 'cat') || (input[i] == 'dog'))){
  obj1[input[i]] = obj1[input[i]] || 0;
  obj1[input[i]]++
}
else if ((input[i] == 'penguin') || (input[i] == 'chicken')){
  obj2[input[i]] = obj2[input[i]] || 0;
  obj2[input[i]]++
}
return {obj1, obj2}

edited Oct 12, 2016 at 17:17

answered Oct 10, 2016 at 18:26

raphael75

3,2686 gold badges35 silver badges49 bronze badges

Collectives™ on Stack Overflow

Counting Elements in an Array, Adding them to 2 Objects within an Array

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related