JavaScript: Split array into groups (array of arrays) based on equal values

Question

I'm trying to do this exercise:

The challenge is to implement a function which adds all together all the consecutive numbers in an array and pushes them into a new array. example: sumConsecutives([1,1,2,1,1,1,1,2,1,1,1]); // -> [2,2,4,2,3]

My idea is to split the array into an array of arrays. So for the above example: [[1,1],[2],[1,1,1,1],[2],[1,1,1]] then go through and reduce them.

I've tried with a while loop and push into a temp variable which then gets pushed if the next number is not the same, to no avail.

Any ideas on how to achieve this?

Answer 1

The easiest approach I could think of... (without map/reduce, though)

var sumConsecutives = function(arr) {
var newArr = [];
var prev = arr[0];
var sum = arr[0];

for (var i=1; i<arr.length; i++){
	if (arr[i] !== prev) {
		newArr[newArr.length] = sum;
		sum = 0;
	}
	sum += arr[i];
	prev = arr[i];
}

// Add last sum
newArr[newArr.length] = sum;

return newArr;
};

console.log ( sumConsecutives([1,1,2,1,1,1,1,2,1,1,1]) );