PROGRAM 8:
XML CODE:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 tools:context=".MainActivity">
 <LinearLayout
 android:id="@+id/linearLayout1"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_alignParentLeft="true"
 android:layout_alignParentRight="true"
 android:layout_alignParentTop="true">
 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="ADDITION"
 android:layout_gravity="center"
 android:textSize="20dp">
 </TextView>
 </LinearLayout>
 <LinearLayout
 android:id="@+id/linearLayout2"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_alignParentLeft="true"
 android:layout_alignParentRight="true"
 android:layout_below="@+id/linearLayout1">
 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="Enter No 1:" />
 <EditText
 android:id="@+id/editText1"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_weight="0.20"
 android:inputType="number">
 </EditText>
 </LinearLayout>
 <LinearLayout
 android:id="@+id/linearLayout3"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_alignParentLeft="true"
 android:layout_alignParentRight="true"
 android:layout_below="@+id/linearLayout2">
 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="Enter No 2:" />
 <EditText
 android:id="@+id/editText2"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_weight="0.20"
 android:inputType="number">
 </EditText>
 </LinearLayout>
 <LinearLayout
 android:id="@+id/linearLayout4"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_alignParentLeft="true"
 android:layout_alignParentRight="true"
 android:layout_below="@+id/linearLayout3">
 <Button
 android:id="@+id/button1"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_weight="0.50"
 android:text="Addition" />
 <Button
 android:id="@+id/button3"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_weight="0.50"
 android:text="Subtraction" />
 <Button android:id="@+id/button2"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_weight="0.50"
 android:text="Clear" />
 </LinearLayout>
 <View
 android:id="@+id/linearLayout5"
 android:layout_width="fill_parent"
 android:layout_height="2px"
 android:background="#DDFFDD" />
</RelativeLayout>
JAVA CODE:
package com.example.prg8;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
 EditText txtData1, txtData2;
 float num1, num2, result1, result2;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 Button add = (Button) findViewById(R.id.button1);
 add.setOnClickListener(new OnClickListener() {
 public void onClick(View v) {
 try {
 txtData1 = (EditText) findViewById(R.id.editText1);
 txtData2 = (EditText) findViewById(R.id.editText2);
 num1 = Float.parseFloat(txtData1.getText().toString());
 num2 = Float.parseFloat(txtData2.getText().toString());
 result1 = num1 + num2;
 Toast.makeText(getBaseContext(), "ANSWER:" + result1,
 Toast.LENGTH_SHORT).show();
 } catch (Exception e) {
 Toast.makeText(getBaseContext(), e.getMessage(),
 Toast.LENGTH_SHORT).show();
 }
 }
 });
 Button sub = (Button) findViewById(R.id.button3);
 sub.setOnClickListener(new OnClickListener() {
 public void onClick(View v) {
 try {
 txtData1 = (EditText) findViewById(R.id.editText1);
 txtData2 = (EditText) findViewById(R.id.editText2);
 num1 = Float.parseFloat(txtData1.getText().toString());
 num2 = Float.parseFloat(txtData2.getText().toString());
 result2 = num1 - num2;
 Toast.makeText(getBaseContext(), "ANSWER:" + result2,
 Toast.LENGTH_SHORT).show();
 } catch (Exception e) {
 Toast.makeText(getBaseContext(), e.getMessage(),
 Toast.LENGTH_SHORT).show();
 }
 }
 });
 Button clear = (Button) findViewById(R.id.button2);
 clear.setOnClickListener(new OnClickListener() {
 public void onClick(View v) {
 try {
 txtData1.setText("");
 txtData2.setText("");
 } catch (Exception e) {
 Toast.makeText(getBaseContext(), e.getMessage(),
 Toast.LENGTH_SHORT).show();
 } } }); }}