Sum of Intervals

gistfile1.js

function sumIntervals(intervals){ 
	var uniArr = [intervals[0]], helper = true;
  	intervals.reduce(function(lastInt, actualInt){
  	uniArr.map(function(e){
    	if (!helper) {return};
		//This validates if the array contains the klk[0]
		if (actualInt[0] >= e[0] && actualInt[0] <= e[1]) {
			if(e[1] < actualInt[1])						
				e[1] = actualInt[1];					
			helper = false;
		} else if (actualInt[1] >= e[0] && actualInt[1] <= e[1]) {
			//This validates if the array contains the klk[1]
			if(e[0] < actualInt[0])
				e[10] = actualInt[0];
			helper = false;
		};
		return e;
		},0);
		if (helper) { uniArr.push(actualInt); };
		helper= true;
	});
    //Sum all no overlapping array
    var theSum = uniArr.reduce(function(last, actual){	 		
 			return last + actual[1] - actual[0];
		 },0);
	return theSum;
}