How do I hide and show a menu item in the Android ActionBar?

This example demonstrates how do I hide and show a menu item in the Android ActionBar.
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"?>
<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"
   android:orientation="vertical"
   android:gravity="center"
   tools:context=".MainActivity">
   <ToggleButton
      android:id="@+id/btnMenuItem"
      android:layout_width="match_parent"
      android:layout_height="wrap_content" />
</LinearLayout>
Step 3 − Add the following code to src/MainActivity.java
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.CompoundButton;
import android.widget.ToggleButton;
public class MainActivity extends AppCompatActivity {
   ToggleButton button1;
   Menu myMenu;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      button1 = findViewById(R.id.btnMenuItem);
      button1.setOnCheckedChangeListener(onCheckedChangeListener);
   }
   CompoundButton.OnCheckedChangeListener onCheckedChangeListener = new CompoundButton.OnCheckedChangeListener() {
      @Override
      public void onCheckedChanged(CompoundButton buttonView,
      boolean isChecked) {
         if(myMenu != null) {
            if (buttonView == button1) {
               myMenu.findItem(R.id.menu_action_share).setVisible(isChecked);
               myMenu.findItem(R.id.menu_action_share).setEnabled(isChecked);
            }
         }
      }
   };
   public boolean onCreateOptionsMenu(Menu menu) {
      MenuInflater inflater = getMenuInflater();
      inflater.inflate(R.menu.menuitem, menu);
      myMenu = menu;
      MenuItem item = menu.findItem(R.id.menu_action_share);
      if (item != null) {
         item.setVisible(true);
      }
   return true;
   }
}
Step 4 − Right click on res, create menu folder. Right click on the menu folder, create a menu resource file (menuitem.xml) and add the following code −
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto">
   <item
      android:id="@+id/menu_action_share"
      android:icon="@drawable/ic_share_black_24dp"
      android:title="Share"
      app:showAsAction="ifRoom"/>
</menu>
Step 5 − Add the following code to androidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.sample">
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>
Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run   icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −
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