Android_Slip_6A

1. Create the layout file (res/layout/activity_main.xml):

<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"
tools:context=".MainActivity">

<EditText
android:id="@+id/editTextNumber1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="Number 1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintHorizontal_bias="0.5"/>

<EditText
android:id="@+id/editTextNumber2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="Number 2"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/editTextNumber1"
app:layout_constraintVertical_bias="0.16"
app:layout_constraintHorizontal_bias="0.5"/>

<Button
android:id="@+id/buttonAdd"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Add"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/editTextNumber2"
app:layout_constraintVertical_bias="0.16"
app:layout_constraintHorizontal_bias="0.5"/>

<Button
android:id="@+id/buttonSubtract"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Subtract"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/buttonAdd"
app:layout_constraintVertical_bias="0.16"
app:layout_constraintHorizontal_bias="0.5"/>

<Button
android:id="@+id/buttonMultiply"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Multiply"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/buttonSubtract"
app:layout_constraintVertical_bias="0.16"
app:layout_constraintHorizontal_bias="0.5"/>

<Button
android:id="@+id/buttonDivide"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Divide"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/buttonMultiply"
app:layout_constraintVertical_bias="0.16"
app:layout_constraintHorizontal_bias="0.5"/>

<TextView
android:id="@+id/textViewResult"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Result: "
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/buttonDivide"
app:layout_constraintVertical_bias="0.16"
app:layout_constraintHorizontal_bias="0.5"/>
</androidx.constraintlayout.widget.ConstraintLayout>

2. MainActivity.java:

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 {

private EditText editTextNumber1,editTextNumber2;
private Button buttonAdd,buttonSubtract,buttonMultiply,buttonDivide;
private TextView textViewResult;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

// Initialize UI elements
editTextNumber1 = findViewById(R.id.editTextNumber1);
editTextNumber2 = findViewById(R.id.editTextNumber2);
buttonAdd = findViewById(R.id.buttonAdd);
buttonSubtract = findViewById(R.id.buttonSubtract);
buttonMultiply = findViewById(R.id.buttonMultiply);
buttonDivide = findViewById(R.id.buttonDivide);
textViewResult = findViewById(R.id.textViewResult);

// Set click listeners for buttons
buttonAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
performOperation('+');
}
});

buttonSubtract.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
performOperation('-');
}
});

buttonMultiply.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
performOperation('*');
}
});

buttonDivide.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
performOperation('/');
}
});
}

private void performOperation(char operator) {
double num1 = parseDoubleOrZero(editTextNumber1.getText().toString());
double num2 = parseDoubleOrZero(editTextNumber2.getText().toString());

double result;
switch (operator) {
case '+':
result = num1 + num2;
break;
case '-':
result = num1 - num2;
break;
case '*':
result = num1 * num2;
break;
case '/':
result = (num2 != 0.0) ? num1 / num2 : Double.NaN;
break;
default:
result = Double.NaN;
}

textViewResult.setText("Result: " + result);
}

private double parseDoubleOrZero(String str) {
try {
return Double.parseDouble(str);
} catch (NumberFormatException e) {
return 0.0;
}
}
}