SOURCE

function Max(arr = []){
    return arr.reduce((t, v) => t > v ? t : v);
}
function Min(arr = []){
    return arr.reduce((t, v) => t < v ? t : v);
}
console.log(Max([12, 45, 21, 65, 38, 76, 108, 43]))
console.log(Min([12, 45, 21, 65, 38, 76, 108, 43]))