private void jbKurangActionPerformed(java.awt.event.ActionEvent evt) {
    int nilai1 = Integer.parseInt(jtNilai1.getText());
    int nilai2 = Integer.parseInt(jtNilai2.getText());
    operator angka = new operator(nilai1,nilai2);
    jtHasil.setText(""+angka.kurang());
    }

    private void jbTambahActionPerformed(java.awt.event.ActionEvent evt) {
    int nilai1 = Integer.parseInt(jtNilai1.getText());
    int nilai2 = Integer.parseInt(jtNilai2.getText());
    operator angka = new operator(nilai1,nilai2);
    jtHasil.setText(""+angka.tambah());

    }

    private void jbKaliActionPerformed(java.awt.event.ActionEvent evt) {
    int nilai1 = Integer.parseInt(jtNilai1.getText());
    int nilai2 = Integer.parseInt(jtNilai2.getText());
    operator angka = new operator(nilai1,nilai2);
    jtHasil.setText(""+angka.kali());
    }

    private void jbBagiActionPerformed(java.awt.event.ActionEvent evt) {
   int nilai1 = Integer.parseInt(jtNilai1.getText());
    int nilai2 = Integer.parseInt(jtNilai2.getText());
    operator angka = new operator(nilai1,nilai2);
    jtHasil.setText(""+angka.bagi());
    }

    private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) {
        System.exit(0);

    }