//  activity_change_fragment_example.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
        tools:context=".ChangeFragmentExample"
        android:padding="16dp"
        android:orientation="vertical">
    
      <Button
           android:id="@+id/change_fragment1"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:text="Change Fragment"
           android:textColor="@color/colorWhite"
           android:background="@color/colorAccent"
           />
   
      <FrameLayout
           android:id="@+id/frameLayout1"
           android:layout_width="match_parent"
           android:layout_height="match_parent"
           android:layout_marginTop="10dp"/>
   
</LinearLayout>


// fragment_fragment_one.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        xmlns:tools="http://schemas.android.com/tools"
        tools:context=".FragmentOne"
        android:background="@color/colorOrange"
        android:gravity="center">
    
      <TextView
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:text="First Fragment"
           android:textColor="@color/colorWhite"
           android:textSize="40sp"/>
   
</LinearLayout>


// fragment_fragment_two.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        xmlns:tools="http://schemas.android.com/tools"
        tools:context=".FragmentTwo"
        android:background="@color/colorAccent"
        android:gravity="center">
    
      <TextView
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:text="Second Fragment"
           android:textColor="@color/colorWhite"
           android:textSize="40sp"/>
   
</LinearLayout>
                                    
                                  

                                    
// ChangeFragmentExample.java


package com.example.widgets;
    
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
    
public class ChangeFragmentExample extends AppCompatActivity {
   
      Button button;
      boolean result=false;
   
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_change_fragment_example);
   
          button=(Button) findViewById(R.id.change_fragment1);
   
          button.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  FragmentManager fragmentManager = getSupportFragmentManager();
                  FragmentTransaction fragmentTransaction=fragmentManager.beginTransaction();
   
                  if (!result){
                      FragmentOne fragment_one=new FragmentOne();
                      fragmentTransaction.replace(R.id.frameLayout1,fragment_one);
                      fragmentTransaction.commit();
                      button.setText("Fragment One");
                      result=true;
                  }else{
                      FragmentTwo fragment_two=new FragmentTwo();
                      fragmentTransaction.replace(R.id.frameLayout1,fragment_two);
                      fragmentTransaction.commit();
                      button.setText("Fragment Two");
                      result=false;
                  }
   
              }
          });   
      }
}



// FragmentOne.java
package com.example.widgets;
   
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
    
public class FragmentOne extends Fragment {
   
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
          // Inflate the layout for this fragment
          return inflater.inflate(R.layout.fragment_fragment_one, container, false);
      }
   
}



// FragmentTwo.java
package com.example.widgets;
    
    
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
    
public class FragmentTwo extends Fragment {
   
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
          // Inflate the layout for this fragment
          return inflater.inflate(R.layout.fragment_fragment_two, container, false);
      }
}
                                    
                                  

                                    
                                      // ChangeFragmentExample.kt
                                      package com.example.widgets
                                      
                                      import android.os.Bundle
                                      import androidx.fragment.app.Fragment
                                      import androidx.fragment.app.FragmentManager
                                      import androidx.fragment.app.FragmentTransaction
                                      import androidx.appcompat.app.AppCompatActivity
                                      import android.view.View
                                      import android.widget.Button
                                      
                                      class ChangeFragmentExample : AppCompatActivity() {
                                      
                                          private lateinit var button: Button
                                          private var result = false
                                      
                                          override fun onCreate(savedInstanceState: Bundle?) {
                                              super.onCreate(savedInstanceState)
                                              setContentView(R.layout.activity_change_fragment_example)
                                      
                                              button = findViewById(R.id.change_fragment1)
                                      
                                              button.setOnClickListener {
                                                  val fragmentManager: FragmentManager = supportFragmentManager
                                                  val fragmentTransaction: FragmentTransaction = fragmentManager.beginTransaction()
                                      
                                                  if (!result) {
                                                      val fragmentOne = FragmentOne()
                                                      fragmentTransaction.replace(R.id.frameLayout1, fragmentOne)
                                                      fragmentTransaction.commit()
                                                      button.text = "Fragment One"
                                                      result = true
                                                  } else {
                                                      val fragmentTwo = FragmentTwo()
                                                      fragmentTransaction.replace(R.id.frameLayout1, fragmentTwo)
                                                      fragmentTransaction.commit()
                                                      button.text = "Fragment Two"
                                                      result = false
                                                  }
                                              }
                                          }
                                      }
                                      
                                      // FragmentOne.kt
                                      package com.example.widgets
                                      
                                      import android.os.Bundle
                                      import androidx.fragment.app.Fragment
                                      import android.view.LayoutInflater
                                      import android.view.View
                                      import android.view.ViewGroup
                                      
                                      class FragmentOne : Fragment() {
                                      
                                          override fun onCreateView(
                                              inflater: LayoutInflater, container: ViewGroup?,
                                              savedInstanceState: Bundle?
                                          ): View? {
                                              // Inflate the layout for this fragment
                                              return inflater.inflate(R.layout.fragment_fragment_one, container, false)
                                          }
                                      }
                                      
                                      // FragmentTwo.kt
                                      package com.example.widgets
                                      
                                      import android.os.Bundle
                                      import androidx.fragment.app.Fragment
                                      import android.view.LayoutInflater
                                      import android.view.View
                                      import android.view.ViewGroup
                                      
                                      class FragmentTwo : Fragment() {
                                      
                                          override fun onCreateView(
                                              inflater: LayoutInflater, container: ViewGroup?,
                                              savedInstanceState: Bundle?
                                          ): View? {
                                              // Inflate the layout for this fragment
                                              return inflater.inflate(R.layout.fragment_fragment_two, container, false)
                                          }
                                      }