Java

for (int i = 0; i < ar.length - 1; i++)

1. for (int i = 0; i < ar.length; i++)
2. for (int j = i+1; j < ar.length; j++)

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Validate extends JFrame
{
	TextField t;
	public Validate()
	{
		t= new TextField(10);
		add(t);
		t.addKeyListener(new KeyAdapter() 
		{
			public void keyPressed(KeyEvent e) 
			{
				int key = e.getKeyCode();
				if ((key == KeyEvent.VK_0))
				{
					JOptionPane.showMessageDialog(null,"0 Was Clicked", "Note",JOptionPane.INFORMATION_MESSAGE);
				}
				else
					if((key == KeyEvent.VK_1)||(key == KeyEvent.VK_2)||(key == KeyEvent.VK_3)||(key == KeyEvent.VK_4)||(key == KeyEvent.VK_5)||(key == KeyEvent.VK_6||(key == KeyEvent.VK_7)||(key == KeyEvent.VK_8)||(key == KeyEvent.VK_9)))
					{
						return;
					}
					else
					{
						JOptionPane.showMessageDialog(null,"Invalid Input", "Note",JOptionPane.WARNING_MESSAGE);
						String s = t.getText();
						t.setText(s.replaceAll(e.getKeyChar()+"",""));
						
					}
			}
		}
		);
		setTitle("Validate");
		setLocationRelativeTo(null);
		pack();
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
	}
	public static void main(String[] args) 
	{
		new Validate();
	}
}

public Validate() 
	{
		Text.addKeyListener(new KeyAdapter() 
		{
			public void keyTyped(KeyEvent e) 
			{
				char c = e.getKeyChar();
				if (!(Character.isDigit(c) ||(c == KeyEvent.VK_BACK_SPACE) ||(c == KeyEvent.VK_DELETE))) 
				{
					getToolkit().beep();
					e.consume();
				}
				if( c == KeyEvent.VK_0)
				{
					Label.setText("0 entered");
					Label.setForeground(Color.red);
				}
				else
				{        	   
					Label.setText("ok");
					Label.setForeground(Color.black);
				}
			}
		});

public class Validate()
{
DoubleValidate dv = new DoubleValidate();
public Validate() 
	{
		Text.setDocument(dv);
		add(Text);
	}

	static class DoubleValidate extends PlainDocument 
	{
		public void insertString(int offset,String string, AttributeSet attributes)throws BadLocationException 
		{
			if (string == null) 
			{
				return;
			} 
			else 
			{
				String newValue;
				int length = getLength();
				
				if (length == 0) 
				{
					newValue = string;
				} 
				else 
				{
					String currentContent = getText(0, length);
					StringBuffer currentBuffer = new StringBuffer(currentContent);
					currentBuffer.insert(offset, string);
					newValue = currentBuffer.toString();
				}
				try 
				{
					Double.parseDouble(newValue);
					super.insertString(offset, string,attributes);
				} 
				catch (NumberFormatException exception) 
				{
					Toolkit.getDefaultToolkit().beep();
				}
			}
		}
	}
}

import java.io.File;
import java.util.*;

public class RegularExpression 
{
	public static void main(String[] args) throws Exception 
	{
		Scanner scan = new Scanner(System.in);
		
		System.out.println("Enter HTML file Name:");
		
		File HtmlFile = new File(scan.next());
		
		Scanner scan2 = new Scanner(HtmlFile);
		
		int FirstIndex =0,LastIndex =0;
		
		ArrayList<String> Bold = new ArrayList<String>();
		
		ArrayList<String> Italics = new ArrayList<String>();
		
		while(scan2.hasNext())
		{
			String q = scan2.nextLine();

			for (int i =0; i <q.length(); i++)
			{
				if (i+3<=q.length())
				{
					if (q.substring(i, i+3).equalsIgnoreCase("<b>"))
					{
						FirstIndex = i+3;

						for (int j = FirstIndex; j <q.length(); j++)
						{
							if (j+4<=q.length())
							{
								if (q.substring(j, j+4).equalsIgnoreCase("</b>"))
								{
									LastIndex = j;
									Bold.add(q.substring(FirstIndex,LastIndex));
									break;
								}
							}
						}
					}
					else
						if (q.substring(i, i+3).equalsIgnoreCase("<i>"))
						{
							for (int j = FirstIndex; j <q.length(); j++)
							{
								if (j+4<=q.length())
								{
									if (q.substring(j, j+4).equalsIgnoreCase("</i>"))
									{
										LastIndex = j;
										Italics.add(q.substring(FirstIndex,LastIndex));
										break;
									}
								}
							}
						}
				}
			}
		}
		
		System.out.println("Bold:");
		
		for (int i =0; i <Bold.size(); i++)
		{
			System.out.println(Bold.get(i));
		}
		
		System.out.println("Italics:");
		
		for (int i =0; i <Bold.size(); i++)
		{
			System.out.println(Italics.get(i));
		}
	}
}