Simple Adding And Subtracting Calcuator Project Android Studio

Step01: Look At the Android MainActivity.java

package com.example.rupom.addsub; import android.content.Intent; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; public class MainActivity extends AppCompatActivity { private Button addButton,subButton; private EditText Text1,Text2; private TextView result; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); addButton= (Button) findViewById(R.id.add); subButton = (Button) findViewById(R.id.sub); Text1= (EditText) findViewById(R.id.editText1); Text2=(EditText) findViewById(R.id.editText2); result= (TextView) findViewById(R.id.resultShow); addButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String num1String=Text1.getText().toString(); String num2String=Text2.getText().toString(); double num1Double=Double.parseDouble(num1String); double num2Double=Double.parseDouble(num2String); double sum = num1Double+num2Double; result.setText(Double.toString(sum)); } }); subButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String num1String=Text1.getText().toString(); String num2String=Text2.getText().toString(); double num1Double=Double.parseDouble(num1String); double num2Double=Double.parseDouble(num2String); double sum = num1Double-num2Double; result.setText(Double.toString(sum)); } }); }

Step02: Look At the Android MainActivity.xml

package com.example.rupom.addsub; <?xml version="1.0" encoding="utf-8"?> <relativelayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.rupom.addsub.MainActivity"> <LinearLayout android:padding="20dp" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical" android:gravity="center_horizontal" android:id="@+id/line1" > <EditText android:hint="First Number" android:layout_width="300dp" android:layout_height="wrap_content" android:id="@+id/editText1" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:inputType="numberDecimal"/> <EditText android:hint="Second Number" android:layout_below="@+id/editText1" android:layout_width="300dp" android:layout_height="wrap_content" android:id="@+id/editText2" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:inputType="numberDecimal"/> <TextView android:padding="20dp" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="New Text" android:id="@+id/resultShow" /> </LinearLayout> <LinearLayout android:layout_below="@+id/line1" android:layout_width="match_parent" android:layout_height="wrap_content" android:gravity="center_horizontal"> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="ADD" android:id="@+id/add" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="SUB" android:id="@+id/sub" /> </LinearLayout> </RelativeLayout>