Fragment

//activity_mail.xml  //container ni error aave to activity main_xml jain ne id container lai leve
<linearlayout android:id="@+id/container" android:layout_height="match_parent" android:layout_width="match_parent" android:orientation="vertical" tools:context="demoproject.aalap.com.fragment.MainActivity" 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">

    <button android:id="@+id/btn1" android:layout_height="wrap_content" android:layout_width="match_parent" android:text="btn1">
    </button><button android:id="@+id/btn2" android:layout_height="wrap_content" android:layout_width="match_parent" android:text="btn2">

</button></linearlayout>
//fragment1.xml khale textview j lkhvu aavi j rete freagment2.xml textview khale levu aema text ma home ne badle koi pn name lkhe devu

    <textview android:layout_height="wrap_content" android:layout_width="match_parent" android:text="home">

//fragment1.java aavi j rete fragment2.java lai levo

public class fragment1 extends Fragment {
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        View view=inflater.inflate(R.layout.fragment1,container,false);
        return view;
    }
}



//MainActivity.java

public class MainActivity extends AppCompatActivity {
    Button btn1,btn2;

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

        btn1=findViewById(R.id.btn1);
        btn2=findViewById(R.id.btn2);

        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                fragment1 f1=new fragment1();
                FragmentManager fm=getFragmentManager();
                FragmentTransaction ft=fm.beginTransaction();
                ft.replace(R.id.container,f1);
                ft.commit();
            }
        });
        btn2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                fragment2 f2=new fragment2();
                FragmentManager fm=getFragmentManager();
                FragmentTransaction ft=fm.beginTransaction();
                ft.replace(R.id.container,f2);
                ft.commit();

            }
        });


    }
}