Intent intent = new Intent(getBaseContext(), SignoutActivity.class);
intent.putExtra("EXTRA_SESSION_ID", sessionId);
startActivity(intent);

String s = getIntent().getStringExtra("EXTRA_SESSION_ID");

Intent i = new Intent(getApplicationContext(), NewActivity.class);

i.putExtra("key","value");
startActivity(i);

Bundle extras = getIntent().getExtras();
if (extras != null) {
    String value = extras.getString("key");
    //The key argument here must match that used in the other activity
}

Intent myIntent = new Intent(this, NewActivity.class);
myIntent.putExtra("firstName", "Your First Name Here");
myIntent.putExtra("lastName", "Your Last Name Here");
startActivity(myIntent)

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view);

    Intent intent = getIntent();

    String fName = intent.getStringExtra("firstName");
    String lName = intent.getStringExtra("lastName");
}

Intent intent = new Intent(getApplicationContext(), SecondActivity.class);
intent.putExtra("Variable name", "Value you want to pass");
startActivity(intent);

long value = getIntent().getLongExtra("Variable name which you sent as an extra", defaultValue(you can give it anything));

String value = getIntent().getStringExtra("Variable name which you sent as an extra");

Boolean value = getIntent().getBooleanExtra("Variable name which you sent as an extra", defaultValue);

import android.content.Intent;

public class IntentHelper {
    public static final Intent createYourSpecialIntent(Intent src) {
          return new Intent("YourSpecialIntent").addCategory("YourSpecialCategory").putExtras(src);
    }
}

IntentHelper.createYourSpecialIntent(getIntent());

IntentHelper.createYourSpecialIntent(getIntent()).putExtra("YOUR_FIELD_NAME", fieldValueToSave);

getIntent().getStringExtra("YOUR_FIELD_NAME");

Intent intent = new Intent(getBaseContext(), NextActivity.class);
Foo foo = new Foo();
intent.putExtra("foo", foo);
startActivity(intent);

Foo foo = getIntent().getExtras().getParcelable("foo");

public class MyActivity extends Activity {

  public static String SharedString;
  public static SomeObject SharedObject;

//...

String str = "My Data"; //Data you want to send
Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtra("name",str); //Here you will add the data into intent to pass bw activites
v.getContext().startActivity(intent);

import android.content.Intent;

String name = this.getIntent().getStringExtra("name");

Intent i = new Intent(this, ActivityTwo.class);
AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.autocomplete);
String getrec=textView.getText().toString();
Bundle bundle = new Bundle();
bundle.putString(“stuff”, getrec);
i.putExtras(bundle);
startActivity(i);

Bundle bundle = getIntent().getExtras();

String stuff = bundle.getString(“stuff”);

SharedPreferences preferences = getSharedPreferences("session",getApplicationContext().MODE_PRIVATE);
Editor editor = preferences.edit();
editor.putString("sessionId", sessionId);
editor.commit();

SharedPreferences preferences = getSharedPreferences("session", getApplicationContext().MODE_PRIVATE);
String sessionId = preferences.getString("sessionId", null);

SharedPreferences settings = context.getSharedPreferences("session", Context.MODE_PRIVATE);
settings.edit().clear().commit();

int n= 10;
 Intent in = new Intent(From_Activity.this,To_Activity.class);
 Bundle b1 = new Bundle();
 b1.putInt("integerNumber",n);
 in.putExtras(b1);
 startActivity(in);

Bundle b2 = getIntent().getExtras();
 int m = 0;
 if(b2 != null)
  {
     m = b2.getInt("integerNumber");
  }

i = new Intent(FirstActivity.this,SecondActivity.class);
i.putExtra("key", value);
startActivity(i)

Bundle bundle= getIntent().getExtras();

Intent intent = new Intent(this, Activity.class);
intent.putExtra("bitmap", bitmap);

Bitmap bitmap = getIntent().getParcelableExtra("bitmap");

SecondFragment fragment = new SecondFragment();
Bundle bundle = new Bundle();
bundle.putParcelable("bitmap", bitmap);
fragment.setArguments(bundle);

Bitmap bitmap = getArguments().getParcelable("bitmap");

Intent intent = new Intent(this, SecondActivity.class);

ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPG, 100, stream);
byte[] bytes = stream.toByteArray();
intent.putExtra("bitmapbytes",bytes);

byte[] bytes = getIntent().getByteArrayExtra("bitmapbytes");
Bitmap bmp = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);

Intent intent = new Intent(YourCurrentActivity.this, YourActivityName.class);
intent.putExtra("NAme","John");
intent.putExtra("Id",1);
startActivity(intent);

int id = getIntent.getIntExtra("id", /* defaltvalue */ 2);

Intent i = getIntent();
String name = i.getStringExtra("name");

/*
 * If you are from transferring data from one class that doesn't
 * extend Activity, then you need to do something like this.
 */

public class abc {
    Context context;

    public abc(Context context) {
        this.context = context;
    }

    public void something() {
        context.startactivity(new Intent(context, anyone.class).putextra("key", value));
    }
}

public class Info
{
    public static int ID      = 0;
    public static String NAME = "TEST";
}

Info.ID
Info.NAME

Info.ID = 5;
Info.NAME = "USER!";

...
<application android:name="MyApplication"
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
....

public class MyApplication extends Application {
    private MainActivity mainActivity;

    @Override
    public void onCreate() {
        super.onCreate();
    }

    public void setMainActivity(MainActivity activity) { this.mainActivity=activity; }
    public MainActivity getMainActivity() { return mainActivity; }
}

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ((MyApplication)getApplication()).setMainActivity(this);
    }
    ...

}

public class MyPreferences extends PreferenceActivity
            implements SharedPreferences.OnSharedPreferenceChangeListener {
    @SuppressWarnings("deprecation")
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);
        PreferenceManager.getDefaultSharedPreferences(this)
            .registerOnSharedPreferenceChangeListener(this);
    }

    @Override
    public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
        if (!key.equals("autostart")) {
            ((MyApplication)getApplication()).getMainActivity().refreshUI();
        }
    }
}

public class HomeIntent extends Intent {

    private static final String ACTION_LOGIN = "action_login";
    private static final String ACTION_LOGOUT = "action_logout";

    private static final String ARG_USERNAME = "arg_username";
    private static final String ARG_PASSWORD = "arg_password";


    public HomeIntent(Context ctx, boolean isLogIn) {
        this(ctx);
        //set action type
        setAction(isLogIn ? ACTION_LOGIN : ACTION_LOGOUT);
    }

    public HomeIntent(Context ctx) {
        super(ctx, HomeActivity.class);
    }

    //This will be needed for receiving data
    public HomeIntent(Intent intent) {
        super(intent);
    }

    public void setUserName(String userName, String password) {
        putExtra(ARG_USERNAME, userName);
        putExtra(ARG_PASSWORD, password);
    }

    public String getUsername() {
        return getStringExtra(ARG_USERNAME);
    }

    public String getPassword() {
        return getStringExtra(ARG_PASSWORD);
    }

    //To separate the params is for which action, we should create action
    public boolean isActionLogIn() {
        return getAction().equals(ACTION_LOGIN);
    }

    public boolean isActionLogOut() {
        return getAction().equals(ACTION_LOGOUT);
    }
}

public class SplashActivity extends AppCompatActivity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);

        String username = "phearum";
        String password = "pwd1133";
        final boolean isActionLogin = true;
        //Passing data to HomeActivity
        startActivity(new HomeIntent(this, isActionLogin));

    }
}

public class HomeActivity extends AppCompatActivity {

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

        //This is how we receive the data from SplashActivity
        //Make sure you pass getIntent() to the HomeIntent constructor
        final HomeIntent homeIntent = new HomeIntent(getIntent());
        Log.d("HomeActivity", "Is action login?  " + homeIntent.isActionLogIn());
        Log.d("HomeActivity", "username: " + homeIntent.getUsername());
        Log.d("HomeActivity", "password: " + homeIntent.getPassword());
    }
}

Intent intent = new Intent(getActivity(), SecondActivity.class);
intent.putExtra(Intent.EXTRA_TEXT, "my text");
startActivity(intent);

Intent intent = getIntent();
String myText = intent.getExtras().getString(Intent.EXTRA_TEXT);

static final String EXTRA_STUFF = "com.myPackageName.EXTRA_STUFF";

Intent intent = new Intent(getActivity(), SecondActivity.class);
intent.putExtra(EXTRA_STUFF, "my text");
startActivity(intent);

Intent intent = getIntent();
String myText = intent.getExtras().getString(FirstActivity.EXTRA_STUFF);

<string name="EXTRA_STUFF">com.myPackageName.MY_NAME</string>

Intent intent = new Intent(getActivity(), SecondActivity.class);
intent.putExtra(getString(R.string.EXTRA_STUFF), "my text");
startActivity(intent);

Intent intent = getIntent();
String myText = intent.getExtras().getString(getString(R.string.EXTRA_STUFF));

Intent mIntent = new Intent(FirstActivity.this, SecondActivity.class);
mIntent.putExtra("data", data);
startActivity(mIntent);

public class DataHolder {

private static DataHolder dataHolder;
private List<Model> dataList;

public void setDataList(List<Model>dataList) {
    this.dataList = dataList;
}

public List<Model> getDataList() {
    return dataList;
}

public synchronized static DataHolder getInstance() {
    if (dataHolder == null) {
       dataHolder = new DataHolder();
    }
    return dataHolder;
}

private List<Model> dataList = new ArrayList<>();
DataHolder.getInstance().setDataList(dataList);

private List<Model> dataList = DataHolder.getInstance().getDataList();

$.prefs(...).put("val1", 123).put("val2", "Hello World!").put("something", 3.34);

$.Intent().put("data", "myData").put("more", 568)...

this.extras()

public class GlobalClass extends Application
{
    private float vitamin_a;


    public float getVitaminA() {
        return vitamin_a;
    }

    public void setVitaminA(float vitamin_a) {
        this.vitamin_a = vitamin_a;
    }
}

GlobalClass gc = (GlobalClass) getApplication();

gc.getVitaminA()

private static Info instance;
private int id;
private String name;

//Private constructor is to disallow instances creation outside create() or getInstance() methods
private Info() {

}

//Method you use to get the same information from any Activity.
//It returns the existing Info instance, or null if not created yet.
public static Info getInstance() {
    return instance;
}

//Creates a new Info instance or returns the existing one if it exists.
public static synchronized Info create(int id, String name) {

    if (null == instance) {
        instance = new Info();
        instance.id = id;
        instance.name = name;
    }
    return instance;
}

//Serializable class

public class YourClass  implements Serializable {
     public long session_id = 0;
}

Intent mIntent = new Intent(getApplicationContext(), LogoutActivity.class);
mIntent.putExtra("session_id", session_id);
startActivity(mIntent);