Đời sinh viên >.<

Lớp học sinh
class HocSinh
{
//thuoc tinh
private String _maHocSinh;
private String _tenHocSinh;
private DateTime _ngaySinh;
private String _diaChi;
private float _diemToan;
private float _diemLy;
private float _diemHoa;
//property
public String MaHocSinh
{
get { return this._maHocSinh; }
set { this._maHocSinh = value; }
}
public String TenHocSinh
{
get { return this._tenHocSinh; }
set { this._tenHocSinh = value; }
}
public DateTime NgaySinh
{
get { return this._ngaySinh; }
set { this._ngaySinh = value; }
}
public String DiaChi
{
get { return this._diaChi; }
set { this._diaChi = value; }
}
public float DiemToan
{
get { return this._diemToan; }
set { this._diemToan = value; }
}
public float DiemLy
{
get { return this._diemLy; }
set { this._diemLy = value; }
}
public float DiemHoa
{
get { return this._diemHoa; }
set { this._diemHoa = value; }
}
//PT khoi tao
public HocSinh()
{
this._maHocSinh = "?";
this._tenHocSinh = "?";
this._ngaySinh = new DateTime(1988, 5, 20);
this._diaChi = "?";
this._diemToan = 0;
this._diemLy = 0;
this._diemHoa = 0;
}
public HocSinh( String maHocSinh,String tenHocSinh,
DateTime ngaySinh,String diaChi,
float diemToan,float diemLy,float diemHoa)
{
this._tenHocSinh = tenHocSinh;
this._maHocSinh = maHocSinh;
this._diaChi = diaChi;
this._ngaySinh = ngaySinh;
this._diemToan = diemToan;
this._diemLy = diemLy;
this._diemHoa = diemHoa;
}
public HocSinh(HocSinh hs)
{
this._maHocSinh = hs._maHocSinh;
this._tenHocSinh = hs._tenHocSinh;
this._ngaySinh = hs._ngaySinh;
this._diaChi = hs._diaChi;
this._diemHoa = hs._diemHoa;
this._diemLy = hs._diemLy;
this._diemToan = hs._diemToan;
}
//Nhap
public void Nhap()
{
Console.Write("nhap MHS:");
this._maHocSinh = Console.ReadLine();
Console.Write("nhap HOTEN:");
this._tenHocSinh = Console.ReadLine();
Console.Write("nhap NGAYSINH:");
String temp = Console.ReadLine();
String[] anstr = temp.Split('/');
int ngay = int.Parse(anstr[0]);
int thang = int.Parse(anstr[1]);
int nam = int.Parse(anstr[2]);
Console.Write("Nhap dia chi: ");
this._diaChi=Console.ReadLine();
this._ngaySinh = new DateTime(nam, thang, ngay);
Console.Write("Nhap diem toan: ");
this._diemToan = float.Parse(Console.ReadLine());
Console.Write("Nhap diem ly: ");
this._diemLy = float.Parse(Console.ReadLine());
Console.Write("Nhap diem hoa: ");
this._diemHoa = float.Parse(Console.ReadLine());

}
public void GanMaHocSinh(String maHocSinh)
{
this._maHocSinh = maHocSinh;
}
public void GanTenHocSinh(String tenHocSinh)
{
this._tenHocSinh = tenHocSinh;
}
public void GanDiaChi(String diaChi)
{
this._diaChi=diaChi;
}
public void GanNgaySinh(DateTime ngaySinh)
{
this._ngaySinh = ngaySinh;
}
public void GanDiemToan(float diemToan)
{
this._diemToan = diemToan;
}
public void GanDiemLy(float diemLy)
{
this._diemToan = diemLy;
}
public void GanDiemHoa(float diemHoa)
{
this._diemHoa = diemHoa;
}
//Xuat
public void Xuat()
{
Console.Write("Ma hoc sinh: {0}",this._maHocSinh);
Console.Write("Ten hoc sinh: {0}",this._tenHocSinh);
Console.Write("Ngay sinh: {0}",this._ngaySinh);
Console.Write("Dia chi: {0}",this._diaChi);
Console.Write("Diem toan: {0}",this._diemToan);
Console.Write("Diem ly: {0}",this._diemLy);
Console.Write("Diem hoa: {0}",this._diemHoa);
}
public String LayMaHocSinh()
{
return this._maHocSinh;
}
public String LayTenhocSinh()
{
return this._tenHocSinh;
}
public String LayDiaChi()
{
return this._diaChi;
}
public DateTime LayNgaySinh()
{
return this._ngaySinh;
}
public float LayDiemToan()
{
return this._diemToan;
}
public float LayDiemLy()
{
return this._diemLy;
}
public float LayDiemHoa()
{
return this._diemHoa;
}
//PT nghiep cu
public float DiemTrungBinh()
{
float diemTB;
diemTB=(this._diemToan + this._diemLy + this._diemHoa) / 3;
return diemTB;
}

}
Lớp mảng học sinh.
class MangHocSinh
{
//thuoc tinh
private HocSinh[] _hSinh;
//property
public HocSinh[] HSinh
{
get { return this._hSinh; }
set{this._hSinh=value;}
}
public HocSinh this[int index]
{
get { return this._hSinh[index]; }
set { this._hSinh[index] = value; }
}
public int N
{
get { return this._hSinh.Length; }
}
//PT khoi tao (ham dung)
public MangHocSinh()
{
this._hSinh=null;
}
public MangHocSinh(params HocSinh[] hSinh)
{
this._hSinh = new HocSinh[hSinh.Length];
for (int i = 0; i < hSinh.Length; i++)
{
this._hSinh = new HocSinh(hSinh);
}
}
public MangHocSinh(int soHSinh)
{
this._hSinh=new HocSinh[soHSinh];
for(int i=0;i<this._hSinh.Length;i++)
{
this._hSinh = new HocSinh();
}

}
public MangHocSinh(MangHocSinh hSinh)
{
this._hSinh = new HocSinh[hSinh._hSinh.Length];
for (int i = 0; i < hSinh._hSinh.Length; i++)
{
this._hSinh = new HocSinh(hSinh._hSinh);
}
}
public void Nhap()
{
Console.Write("Nhap so hoc sinh: ");
int n=int.Parse(Console.ReadLine());
this._hSinh=new HocSinh[n];
for (int i = 0; i < this._hSinh.Length; i++)
{
this._hSinh = new HocSinh();
Console.WriteLine("Hoc sinh thu {0}", i + 1);
this._hSinh.Nhap();
}
}
public void Xuat()
{
foreach(HocSinh hSinh in this._hSinh )
{
hSinh.Xuat();
}
}
public HocSinh TuoiNhoNhat()
{
HocSinh hSinh = new HocSinh();
DateTime dTime = this._hSinh[0].NgaySinh;
for (int i = 0; i < this._hSinh.Length; i++)
{
if ((DateTime.Now.Year - dTime.Year) > (DateTime.Now.Year - this._hSinh.NgaySinh.Year))
dTime = this._hSinh.NgaySinh;
hSinh = new HocSinh(this._hSinh);
}
return hSinh;
}
public HocSinh DiemTrungBinhLonNhat()
{
HocSinh hSinh = new HocSinh();
float diemTB = 0;
for (int i = 0; i < this._hSinh.Length; i++)
{
if (diemTB<this._hSinh.DiemTrungBinh() )
{
diemTB = this._hSinh.DiemTrungBinh();
hSinh=new HocSinh(this._hSinh);
}
}
return hSinh;
}
}