Add two numbers in android Studio java

I'm creating a button in Android Studio which adds two numbers when cicked on it in Android Studio but it is giving the error. Can you help me? I am a beginner in Android development.

d4.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String str=inputField.getText().toString(); char[] ch=str.toCharArray(); int i; for(i=0; i<ch.length; i++){ if(ch[i]=='+'){int Add=ch[i-1]+ch[i+1]; inputField.setText(Add);} } } });

d4 is the id of the button and inputField is the id of the EditText

This example demonstrates I’ll show you how to add two EditText values in Android using Java.

Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:padding="4dp"> <TextView android:id="@+id/textResult" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_marginTop="70dp" android:background="#008080" android:padding="5dp" android:text="Code4Example" android:textColor="#fff" android:textSize="24sp" android:textStyle="bold" /> <EditText android:id="@+id/editNum1" android:inputType="number" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_centerInParent="true" /> <EditText android:id="@+id/editNum2" android:inputType="number" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/editNum1" android:layout_centerInParent="true" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@+id/editNum2" android:layout_centerInParent="true" android:onClick="addNumbers" android:text="Add Numbers" /> </RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:padding="4dp">

<TextView

android:id="@+id/textResult"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_centerHorizontal="true"

android:layout_marginTop="70dp"

android:background="#008080"

android:padding="5dp"

android:text="Code4Example"

android:textColor="#fff"

android:textSize="24sp"

android:textStyle="bold" />

<EditText

android:id="@+id/editNum1"

android:inputType="number"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_centerInParent="true" />

<EditText

android:id="@+id/editNum2"

android:inputType="number"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_below="@+id/editNum1"

android:layout_centerInParent="true" />

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_below="@+id/editNum2"

android:layout_centerInParent="true"

android:onClick="addNumbers"

android:text="Add Numbers" />

</RelativeLayout>

Step 3 − Add the following code to src/MainActivity.java

Java

import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.EditText; import android.widget.TextView; public class MainActivity extends AppCompatActivity { EditText editNum1,editNum2; TextView textResult; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void addNumbers(View view){ editNum1= findViewById(R.id.editNum1); editNum2= findViewById(R.id.editNum2); textResult= findViewById(R.id.textResult); double num1 = Double.parseDouble(editNum1.getText().toString()); double num2 = Double.parseDouble(editNum2.getText().toString()); double result = num1 + num2; textResult.setText(Double.toString(result)); } }