Android Studio: Passing Variable between Activities

// in 1 activity ->
String idValue = "hellow world";
Intent intent = new Intent(getApplicationContext(), SecondActivity.class);
intent.putExtra("ID", idValue);
startActivity(intent);

//in second Activity->
String i = getIntent().getStringExtra("ID");

Alternatif

In your current Activity, create a new Intent:

String value="Hello world";
Intent i = new Intent(CurrentActivity.this, NewActivity.class);    
i.putExtra("key",value);
startActivity(i);

Then in the new Activity, retrieve those values:

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

Use this technique to pass variables from one Activity to the other.

Referensi

• https://stackoverflow.com/questions/2091465/how-do-i-pass-data-between-activities-in-android-application