How to write HelloWorld in C?

HelloWorld.c

#include <stdio.h>
int main() {
  printf("Hello world!\n");
}

HelloWorld in C++

HelloWorld.cpp

#include <iostream>

using namespace std;

int main() {
cout << "HelloWorld" << endl;
return 0;
}

HelloWorld in Java

For a pure Java HelloWorld:

HelloWorld.java

public class HelloWorld {
 public static void main(String[] args) {
  System.out.println("HelloWorld");
 }
}

javac HellWorld.java

java HelloWorld

HelloWorld in Android

1) Download Eclipse IDE: http://www.eclipse.org/downloads/
2) Download Android SDK for Eclipse: http://developer.android.com/sdk/index.html
-Installing Setup: http://developer.android.com/sdk/installing.html
3) Beginning Tutorial: http://developer.android.com/resources/tutorials/hello-world.html

HelloWorld.java

location: HelloWorld > src > com.HelloWord > HelloWorld.java

package com.HelloWorld;

import android.app.Activity;
import android.os.Bundle;

public class Hello extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
    }

}

main.xml

location: HelloWorld > res > layout > main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
</LinearLayout>

strings.xml

location: HelloWorld > res > values > strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">Hello World, Hello!</string>
    <string name="app_name">HelloWorld</string>
</resources>

AndroidManifest.xml

location: HelloWorld > AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.HelloWorld"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="3" />

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".Hello"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
</manifest>

Notice: "System.out.println("HelloWorld!");" is not being used because "HelloWorld" is a string pulled from "strings.xml" which is used in the "main.xml"