<androidx.constraintlayout.widget.ConstraintLayout 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="match_parent" android:layout_height="match_parent" android:background="#8BC34A" android:backgroundTint="@android:color/darker_gray" tools:context=".MainActivity">

<TextView
	android:id="@+id/textView"
	android:layout_width="133dp"
	android:layout_height="28dp"
	android:layout_marginStart="139dp"
	android:layout_marginLeft="139dp"
	android:layout_marginTop="16dp"
	android:layout_marginEnd="139dp"
	android:layout_marginRight="139dp"
	android:layout_marginBottom="559dp"
	android:background="#0F9D58" 

	android:text="myFirstApp" 
	android:textAppearance="@style/TextAppearance.AppCompat.Medium" 
	app:layout_constraintBottom_toBottomOf="parent" 
	app:layout_constraintEnd_toEndOf="parent" 
	app:layout_constraintStart_toStartOf="parent" 
	app:layout_constraintTop_toTopOf="parent" /> 

<TextView
	android:layout_width="194dp"
	android:layout_height="43dp"
	android:layout_marginStart="114dp"
	android:layout_marginLeft="114dp"
	android:layout_marginTop="58dp"
	android:layout_marginEnd="103dp"
	android:layout_marginRight="103dp"
	android:layout_marginBottom="502dp"
	android:scrollbarSize="30dp"
	android:text=" Calculator"
	android:textAppearance="@style/TextAppearance.AppCompat.Body1"
	android:textSize="30dp"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" /> 

<EditText
	android:id="@+id/num1"
	android:layout_width="364dp"
	android:layout_height="28dp"
	android:layout_marginStart="72dp"
	android:layout_marginTop="70dp"
	android:layout_marginEnd="71dp"
	android:layout_marginBottom="416dp"
	android:background="@android:color/white"
	android:ems="10"
	android:hint="Number1(0)"
	android:inputType="number"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" /> 

<EditText
	android:id="@+id/num2"
	android:layout_width="363dp"
	android:layout_height="30dp"
	android:layout_marginStart="72dp"
	android:layout_marginTop="112dp"
	android:layout_marginEnd="71dp"
	android:layout_marginBottom="374dp"
	android:background="@android:color/white"
	android:ems="10"
	android:hint="number2(0)"
	android:inputType="number"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" /> 

<TextView
	android:id="@+id/result"
	android:layout_width="356dp"
	android:layout_height="71dp"
	android:layout_marginStart="41dp"
	android:layout_marginTop="151dp"
	android:layout_marginEnd="48dp"
	android:layout_marginBottom="287dp"
	android:background="@android:color/white"
	android:text="result"
	android:textColorLink="#673AB7"
	android:textSize="25sp"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" /> 


<Button
	android:id="@+id/sum"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:layout_marginStart="16dp"
	android:layout_marginTop="292dp"
	android:layout_marginEnd="307dp"
	android:layout_marginBottom="263dp"
	android:backgroundTint="@android:color/holo_red_light"
	android:onClick="doSum"
	android:text="+"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" /> 

<Button
	android:id="@+id/sub"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:layout_marginStart="210dp"
	android:layout_marginTop="292dp"
	android:layout_marginEnd="113dp"
	android:layout_marginBottom="263dp"
	android:backgroundTint="@android:color/holo_red_light"
	android:onClick="doSub"
	android:text="-"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" /> 

<Button
	android:id="@+id/div"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:layout_marginStart="307dp"
	android:layout_marginTop="292dp"
	android:layout_marginEnd="16dp"
	android:layout_marginBottom="263dp"
	android:backgroundTint="@android:color/holo_red_light"
	android:onClick="doDiv"
	android:text="/"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintHorizontal_bias="0.0"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" /> 

<Button
	android:id="@+id/mul"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:layout_marginStart="16dp"
	android:layout_marginTop="356dp"
	android:layout_marginEnd="307dp"
	android:layout_marginBottom="199dp"
	android:backgroundTint="@android:color/holo_red_light"
	android:onClick="doMul"
	android:text="x"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" /> 

<Button
	android:id="@+id/button"
	android:layout_width="92dp"
	android:layout_height="48dp"
	android:layout_marginStart="113dp"
	android:layout_marginTop="356dp"
	android:layout_marginEnd="206dp"
	android:layout_marginBottom="199dp"
	android:backgroundTint="@android:color/holo_red_light"
	android:onClick="doMod"
	android:text="%(mod)"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" /> 

<Button
	android:id="@+id/pow"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:layout_marginStart="113dp"
	android:layout_marginTop="292dp"
	android:layout_marginEnd="210dp"
	android:layout_marginBottom="263dp"
	android:backgroundTint="@android:color/holo_red_light"
	android:onClick="doPow"
	android:text="n1^n2"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" /> 

</androidx.constraintlayout.widget.ConstraintLayout>

package com.example.gfg_my_first_app;

import androidx.appcompat.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 {

EditText e1, e2; 
TextView t1; 
int num1, num2; 

@Override
protected void onCreate(Bundle savedInstanceState) 
{ 
	super.onCreate(savedInstanceState); 

	setContentView(R.layout.activity_main); 
} 

public boolean getNumbers() 
{ 

	
	e1 = (EditText)findViewById(R.id.num1); 

	
	e2 = (EditText)findViewById(R.id.num2); 

	t1 = (TextView)findViewById(R.id.result); 


	s1 = e1.getText().toString(); 

	s2 = e2.getText().toString(); 


	if ((s1.equals(null) && s2.equals(null)) 
		|| (s1.equals("") && s2.equals(""))) { 

		String result = "Please enter a value"; 
		t1.setText(result); 

		return false; 
	} 
	else { 
		num1 = Integer.parseInt(e1.getText().toString()); 

		num2 = Integer.parseInt(e2.getText().toString()); 
	} 

	return true; 
} 


public void doSum(View v) 
{ 

	if (getNumbers()) { 
		int sum = num1 + num2; 
		t1.setText(Integer.toString(sum)); 
	} 
} 

public void doPow(View v) 
{ 

	if (getNumbers()) { 
		double sum = Math.pow(num1, num2); 
		t1.setText(Double.toString(sum)); 
	} 
} 


public void doSub(View v) 
{ 

 
	if (getNumbers()) { 
		int sum = num1 - num2; 
		t1.setText(Integer.toString(sum)); 
	} 
} 

public void doMul(View v) 
{ 

	if (getNumbers()) { 
		int sum = num1 * num2; 
		t1.setText(Integer.toString(sum)); 
	} 
} 

public void doDiv(View v) 
{ 

	 
	if (getNumbers()) { 

		double sum = num1 / (num2 * 1.0); 
		t1.setText(Double.toString(sum)); 
	} 
} 

public void doMod(View v) 
{ 


	if (getNumbers()) { 
		double sum = num1 % num2; 
		t1.setText(Double.toString(sum)); 
	} 
} 

}