Given an array of positive integers and a target integer, find if there is a consecutive subarray that sums to the target. E.g, given {5,6,4,12}, findsum(10)=true, findsum(11)=false.

findSubarraySum.js

/*
 Given an array of positive integers and a target integer, find if there is a consecutive subarray that sums to the target. 
 E.g, given {5,6,4,12}, findsum(10)=true, findsum(11)=false.
 http://www.glassdoor.com/Interview/Given-an-array-of-positive-integers-and-a-target-integer-find-if-there-is-a-consecutive-subarray-that-sums-to-the-target-QTN_984284.htm
*/

function findSubarraySum(numbers, sum) {    
    var sumSoFar = 0;
    var start = 0;
    var end = 0;
    while (start < numbers.length) {
        if (sumSoFar == sum) {
            return true;
        } else if (sumSoFar > sum) {
            sumSoFar -= numbers[start];
            start++;
        } else if (end < numbers.length) {
            sumSoFar += numbers[end];
            end++;
        }
    }

    return (sumSoFar == sum);
}

console.log(findSubarraySum([5,6,4,12], 11));