Change Actionbar title of an activity programmatically in Android Studio

In this tutorial we will change the title of Actionbar of an activity using android studio...

Step 1: Create a new project or open your project

Step 2: activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    tools:context=".MainActivity">

    <TextView
        android:text="Hello World!"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

Step 3: MainActivity.java

package com.blogspot.devofandroid.myapplication;

import android.os.Bundle;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

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

        //set actionbar title
        ActionBar actionBar = getSupportActionBar();
        actionBar.setTitle("New Title");

    }
}

Step 4: Output: