Solution to this daily challenge: https://www.reddit.com/r/dailyprogrammer/comments/dv0231/20191111_challenge_381_easy_yahtzee_upper_section/?utm_source=share&utm_medium=web2x

upperSectionScore.js

function upperSectionScore(diceResult){
	// handle empty array
	if(diceResult.length === 0){
		return -1;
	}
	// will need a way to count the frequency of each number
	// a variable to store/return the value, and store the largest num freq
	let frequency = {
		'1': 0,
		'2': 0,
		'3': 0,
		'4': 0,
		'5': 0,
		'6': 0
	},
	largestFreqNum = 1,
	score = 1;

	// TODO:
	// 1) loop thru each roll, counting the frequency of each number rolled
	// 2) find the largestFreqNum num 
	// 3) using the largestFreqNum, calculate the value and return the score.
	diceResult.forEach((roll, idx) => {
		// 1)
		frequency[roll] += 1;
		let numToCompare = diceResult[idx];
        // 2)
		if(frequency[largestFreqNum] <= frequency[numToCompare]){
			largestFreqNum = numToCompare;
		}
	});

    // 3)
	score = largestFreqNum * frequency[largestFreqNum];

	return score;
}


console.log(upperSectionScore([2, 3, 5, 5, 6])); // 10
console.log(upperSectionScore([1, 1, 1, 1, 1])); // 5
console.log(upperSectionScore([]));  // -1
console.log(upperSectionScore([2, 4, 3, 4, 4])); // 12
console.log(upperSectionScore([6, 6, 6, 6, 6])); // 30
console.log(upperSectionScore([1, 1, 3, 2, 3])); // 6