Kotlin : Hello World Android App (Post 7)

Hi ,

After the basic of Kotlin App. Let's start android development with Kotlin language. In this post I am going to share the demo for simple hello world program with Kotlin language.

For setup of Kotlin Support , android studio will be required of 3.0 version and more.At the time of language selection , we need to select "kotlin" for programming language , when we create a new application.

When creating the android application with kotlin , we do not need to change the layouts , just src files will be changed.

Here I will just create one layout having textview in it ,and attach the activity with this textview . Let's have a look :

activity_main.xml :

<?xml version="1.0" encoding="utf-8"?>

<android.support.constraint.ConstraintLayout 

 xmlns:android="http://schemas.android.com/apk/res/android" 

 xmlns:tools="http://schemas.android.com/tools"

 xmlns:app="http://schemas.android.com/apk/res-auto"  

      android:layout_width="match_parent"  

      android:layout_height="match_parent" 

       tools:context=".MainActivity">

    <TextView    

      android:id="@+id/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:

package com.kotlindemo

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)
    }
}

Run the code:

That's it for this post , in next post I will discuss how TextViews and EditText is used in Kotlin.