Kalkulator Sederhana Project

Desain Kalkulator :

Coding di MainActivity.java

package com.example.tombolitung;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.View;

import android.widget.*;

public class MainActivity extends Activity implements Button.OnClickListener {

       Button bPlus, bMinus, bBagi, bKali ;

       EditText etAngka1, etAngka2, etHasil ;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

       

        bPlus = (Button) findViewById (R.id.btnPlus);

        bMinus       = (Button) findViewById (R.id.btnMinus);

        bBagi = (Button) findViewById (R.id.btnBagi);

        bKali = (Button) findViewById (R.id.btnKali);

       

        etAngka1 = (EditText) findViewById (R.id.editText1);

        etAngka2 = (EditText) findViewById (R.id.EditText2);

        etHasil  = (EditText) findViewById (R.id.EditText3);

       

        bPlus.setOnClickListener(this);

        bMinus.setOnClickListener(this);

        bBagi.setOnClickListener(this);

        bKali.setOnClickListener(this);

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.main, menu);

        return true;

    }

       @Override

       public void onClick(View hitung) {

              // TODO Auto-generated method stub

             

              String varAngka1 = etAngka1.getText().toString();

              String varAngka2 = etAngka2.getText().toString();

             

              switch (hitung.getId())

              {

             

              case R.id.btnPlus:

                     if (!varAngka1.equals("")||!varAngka2.equals("")){

                           String varHasil = tambah (varAngka1, varAngka2);

                           etHasil.setText(varHasil);

                     }

                     else {

                           Toast.makeText(this, "Error",Toast.LENGTH_SHORT).show();

                     }

                     break ;

                    

              case R.id.btnMinus:

                     if (!varAngka1.equals("")||!varAngka2.equals("")){

                           String varHasil = kurang (varAngka1, varAngka2);

                           etHasil.setText(varHasil);

                     }

                     else {

                           Toast.makeText(this, "Error",Toast.LENGTH_SHORT).show();

                     }

                     break ;

                    

              case R.id.btnBagi:

                     if (!varAngka1.equals("")||!varAngka2.equals("")){

                           String varHasil = bagi (varAngka1, varAngka2);

                           etHasil.setText(varHasil);

                     }

                     else {

                           Toast.makeText(this, "Error",Toast.LENGTH_SHORT).show();

                     }

                     break ;

                    

              case R.id.btnKali:

                     if (!varAngka1.equals("")||!varAngka2.equals("")){

                           String varHasil = kali (varAngka1, varAngka2);

                           etHasil.setText(varHasil);

                     }

                     else {

                           Toast.makeText(this, "Error",Toast.LENGTH_SHORT).show();

                     }

                     break ;

                    

              }

       }

       private String tambah (String a, String b) {

              // TODO Auto-generated method stub

              Double abc1 = Double.parseDouble(a);

              Double abc2 = Double.parseDouble(b);

              Double dhasil = abc1 + abc2 ;

              String hasil = String.valueOf(dhasil);

              return hasil;

       }

       private String kurang(String a, String b) {

              // TODO Auto-generated method stub

              Double abc1 = Double.parseDouble(a);

              Double abc2 = Double.parseDouble(b);

              Double dhasil = abc1 - abc2 ;

              String hasil = String.valueOf(dhasil);

              return hasil;

       }

       private String bagi (String a, String b) {

              // TODO Auto-generated method stub

              Double abc1 = Double.parseDouble(a);

              Double abc2 = Double.parseDouble(b);

              Double dhasil = abc1 / abc2 ;

              String hasil = String.valueOf(dhasil);

              return hasil;

              }

       private String kali(String a, String b) {

              // TODO Auto-generated method stub

              Double abc1 = Double.parseDouble(a);

              Double abc2 = Double.parseDouble(b);

              Double dhasil = abc1 * abc2 ;

              String hasil = String.valueOf(dhasil);

              return hasil;

       }

   

}

Hasil RUN di Emulator :

SEMOGA BERMANFAAT

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