You can implement the android app by using android studio IDE(Integrated Development Environment). For implementing Hello World app first we need to set up a development environment using android studio IDE which is provided by Google. If you don’t know how to set up an android environment you can refer our Android Environment Setup tutorial.
Once you are done with the installation of Android Studio, open android studio and that will be like as shown below.
Now click on the “New Project” option from the above options, then the next screen will open where we have to mention our project name and project location and the package name will be created automatically.
After entering all the details click on the Next button, if we click on the next button another screen will appear where we have to select the different platforms and SDK targets as shown below.
Now click the Next button to select the particular Activity of your requirement. If we will select the “Basic Activity”, then it will show the basic activity in your layout. If we select other options, then it will show the activity which we have chosen. Here we are selecting Basic Activity like as shown below.
At the final stage, it will an open development tool to write the application code.
Directories and Files of the Android Project:
Before running your app, you should know a few directories and files in the Android project.
- Java: It contains the .java source files for your project and by default, it includes a MainActivity.java source file which has an activity class that runs when your app is launched using the app icon.
- res/drawable-hdpi: It is a directory for drawable objects that are designed for high-density screens.
- res/layout: It is a directory for files that define your app's user interface.
- res/values: This directory is for other various XML files that contain a collection of resources, such as strings and color definitions.
- AndroidManifest.xml: It is the manifest file that describes the fundamental characteristics of the app and defines each of its components.
- Build.gradle: It is an auto-generated file which contains compileSdkVersion, buildToolsVersion, applicationId, minSdkVersion, targetSdkVersion, versionCode, and versionName.