Create a Frame In java

import javax.swing.*;   // swing class is placed in the javax.swing package
public class Main
{
    public static void main(String[] args)
{
          EmpetyFrame f = new EmpetyFrame(); 
// we create a sub class wd class name empetyframe                      
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// exit upon close event operation

        f.setVisible(true);
 // to show the frame main method calls setvisible method

}
}
class EmpetyFrame extends JFrame
{
public EmpetyFrame( ) 
// constructor sets size
{
setSize(default_width,default_height);
}
public static final int default_width = 300;
public static final int default_height = 300;
}

Java Tutorial... How to write code for determining Strings starts or ends with particular substring ?

public class Main
{
    public static void main(String[] args)
{
String[] a={"sell","well","help","hell"} ; // Array of strings
for(String x:a)
if(x.startsWith("he"))
System.out.printf(" Strings that starts with he :" + x +"\n");
for(String x:a)
if(x.endsWith("ll"))
System.out.printf(" Strings that ends with ll :" + x + "\n");

   
}
}