Pemograman Berorientasi Objek

import javax.swing.JOptionPane;
public class sitihalisa
{
public static void main(String[] args)
{
String nilai_UAS;
String nilai_MID;
String nilai_tugas;
float i;
float j;
float k;
float NA;
nilai_UAS=JOptionPane.showInputDialog ("masukkan nilai UAS: ");
nilai_MID=JOptionPane.showInputDialog ("masukkan nilai MID: ");
nilai_tugas=JOptionPane.showInputDialog ("masukkan nilai tugas: ");
i=Float.parseFloat(nilai_UAS);
j=Float.parseFloat(nilai_MID);
k=Float.parseFloat(nilai_tugas);
NA=(0.5f*i)+(0.3f*j)+(0.2f*k);
if (NA>=90)
{
JOptionPane.showMessageDialog(null,"hasil nilai anda"+NA,"hasil nilai",JOptionPane.PLAIN_MESSAGE);
JOptionPane.showMessageDialog(null,"Nilai Angka: A \n \t anda lulus ISTIMEWA","nilai angka",JOptionPane.PLAIN_MESSAGE);
}
else
if (NA>=80)
{
JOptionPane.showMessageDialog(null,"hasil nilai anda"+NA,"hasil nilai",JOptionPane.PLAIN_MESSAGE);
JOptionPane.showMessageDialog(null,"Nilai Angka: B \n \t anda Lulus BAIK","nilai angka",JOptionPane.PLAIN_MESSAGE);
}
else
if (NA>=70)
{
JOptionPane.showMessageDialog(null,"hasil nilai anda"+NA,"hasil nilai",JOptionPane.PLAIN_MESSAGE);
JOptionPane.showMessageDialog(null,"Nilai Angka anda: C \n \t anda Lulus BERSYARAT","nilai angka",JOptionPane.PLAIN_MESSAGE);
}
else
if (NA>=60)
{
JOptionPane.showMessageDialog(null,"hasil nilai anda"+NA,"hasil nilai",JOptionPane.PLAIN_MESSAGE);
JOptionPane.showMessageDialog(null,"Nilai Angka anda: D \n \t anda GAGAL","nilai angka",JOptionPane.PLAIN_MESSAGE);
}
else
if (NA<=50)
{
JOptionPane.showMessageDialog(null,"hasil nilai anda"+NA,"hasil nilai",JOptionPane.PLAIN_MESSAGE);
JOptionPane.showMessageDialog(null,"Nilai Angka anda: E \n \t anda GAGAL TOTAL","nilai angka",JOptionPane.PLAIN_MESSAGE);
}
}
}