Major Scale

function note_number_to_name(number) {
    var pitch_class = ['c','d','e','f','g','a','b'];
    var pitch_d = [0,2,4,5,7,9,11];
    var str = ""

    var octave = Math.trunc((number/12) - 1);

    var pitch = number % 12;

    var index = -1;
    for(var i = 0; i< pitch_class.length;i++) {
        if(pitch_d== pitch) {
            index = i;
            break;
        }
    }

    if(index != -1) {//It means there is no sharp #
        str = str + pitch_class[index];
        str = str + octave;
    } else{
        pitch = (number - 1) % 12;
        for(var i = 0; i< pitch_class.length;i++) {
            if(pitch_d== pitch) {
                index = i;
                break;
            }
        }
        str = str + pitch_class[index];
        str = str + '#';
        str = str + octave;
    }

    str = str.toUpperCase();
    return str;
}

function note_name_to_number(note) {
    note = note.toLowerCase();
    var pitch_class = ['c','d','e','f','g','a','b'];
    var pitch_d = [0,2,4,5,7,9,11];

    var octave = parseInt(note[note.length-1]);

    var pitch_index = 0;
    for(pitch_index = 0; pitch_index< pitch_class.length; pitch_index++) {
        if(pitch_class[pitch_index] == note[0]) {
            break;
        }
    }

    var acc_index = 0;
    note = note.toUpperCase();
    if(note.length == 3) {
        return((octave+1)*12+pitch_d[pitch_index]+1)
    } else {
        return((octave+1)*12+pitch_d[pitch_index])
    }
}

function major_scale(note){
    note_number = note_name_to_number(note);
    var add_note = [0,2,4,5,7,9,11,12];
    var major = [];
    for(var i=0; i<add_note.length;i++) {
        major = note_number_to_name(note_number+add_note);
    }
    return major;
}