Industrial Training




Kotlin Hello World App


Let?s develop a first hello word application on Android studio using Kotlin programming language. To develop android application launch Android Studio and select option 'Start a new Android Studio project'.



Provide a application name ('Hello World' in my case) and check 'Include Kotlin support' and proceed.



Select API level for android application and click next.



Select Activity type and click next.



activity_main.xml

Create an activity_main.xml file in layout folder and add the following code.


< ?xml version="1.0" encoding="utf-8"?>  
< android.support.constraint.ConstraintLayout 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"  
    tools:context="example.app.javatpoint.helloworld.MainActivity">  
  
    < TextView  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:text="Hello World!"  
        app:layout_constraintBottom_toBottomOf="parent"  
        app:layout_constraintLeft_toLeftOf="parent"  
        app:layout_constraintRight_toRightOf="parent"  
        app:layout_constraintTop_toTopOf="parent" />  
  
< /android.support.constraint.ConstraintLayout>  

MainActivity.kt

Create MainActivity.kt file in example.app.javatpoint.helloworld package add the following code.


package example.app.javatpoint.helloworld  
  
import android.support.v7.app.AppCompatActivity  
import android.os.Bundle  
  
class MainActivity : AppCompatActivity() {  
  
    override fun onCreate(savedInstanceState: Bundle?) {  
        super.onCreate(savedInstanceState)  
        setContentView(R.layout.activity_main)  
    }  
}  

Now run your app.



Output:



Hi I am Pluto.