Java how to pass string between activities android

To pass a string value between activities in Android, you can use an Intent object and the putExtra method to put the string value in the Intent object as an extra.

Here is an example of how you can pass a string value between activities in Android:

import android.content.Intent;

public class MainActivity extends AppCompatActivity {
    private String message;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        message = "Hello, World!";
    }
    
    public void openActivity(View view) {
        Intent intent = new Intent(this, SecondActivity.class);
        intent.putExtra("MESSAGE", message);
        startActivity(intent);
    }
}

In this example, the MainActivity activity has a string field called message, and a method called openActivity that is called when a button is clicked. The openActivity method creates an Intent object and puts the message field in the Intent object as an extra using the putExtra method. The SecondActivity class is specified as the target activity, and the Intent object is used to start the SecondActivity.

To get the string value from the Intent object in the SecondActivity class, you can use the getStringExtra method of the Intent class:

import android.content.Intent;

public class SecondActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
        
        Intent intent = getIntent();
        String message = intent.getStringExtra("MESSAGE");
        // Do something with the message...
    }
}

In this example, the SecondActivity class gets the Intent object in the onCreate method using the getIntent method and retrieves the string value from the Intent object using the getStringExtra method. The getStringExtra method takes one argument: the name of the extra.

Keep in mind that this is just one way to pass a string value between activities in Android. You can use different methods and techniques to achieve the same result, such as using a Bundle object to store the string value and pass it to the Intent object, or using a global variable to store the string value and access it from any activity.