let scoreList = [['S1', 10], ['S2', 6], ['S3', 8], ['S4', 7], ['S5', 6], ['S6', 8], ['S7', 6], ['S8', 3]]
function getRankList(scoreList) {
let descendOrder = scoreList.sort(function(x, y) {
return y[1] - x[1];
});
let listRank = descendOrder;
for (let i = 0; i < descendOrder.length; i++) {
listRank[i].push(i);
}
listRank[0][2] = 1;
for (let i = 1; i < descendOrder.length; i++) {
if (listRank[i][1] === listRank[i-1][1]) {
listRank[i][2] = listRank[i-1][2];
}
else {
listRank[i][2] = i+1;
}
}
for (let i = 0; i < listRank.length; i++) {
listRank[i].splice(1,1);
}
return listRank;
}
console.log(getRankList(scoreList));
console