While Loops

         fred = 0;
         while (fred <29)
         { System.out.println(“Hi”);
            fred ++;
         }

These types of statements handle iteration or repetition.
No semi colon after the Boolean expression. They only go after the statements.
fred++ is the same as fred = fred + 1;
It needs { } around the statements that are to be repeated.
The loop has three parts: fred = 0; initializes the variable outside the loop. (fred < 29) is the stopping condition that is tested once at the start of every loop. fred++ is the progression toward the stopping condition.
If any of the three parts of the loop are missing, the loop will not run properly. There could be an infinite loop (it will run forever).

A String based stop:

Enter your name: Joe
Hello, Joe, how are you?
Do you want to be greeted again? (y/n) y
Enter your name: Melvin
Hello, Melvin, how are you?
Do you want to be greeted again? (y/n) y
Enter your name: Sarah
Hello, Sarah, how are you?
Do you want to be greeted again? (y/n) n
Good bye!

public class stopYet
{
   public static void main (String args [])
   {
   new stopYet ();
   }

   public stopYet ()
   {
   String continu = "y";
   while (continu.equals ("y") || continu.equals ("Y"))
   {
   String name = IBIO.inputString ("Enter your name: ");
   System.out.println ("Hello, " + name + ", how are you?");
   continu = IBIO.inputString ("Do you want to be greeted again? (y/n) ");
   }
   
   System.out.println("Good bye!");
   }
}

A longer program:

Starting count down:
1
2
3
4
5
6
7
8
9
10

Ooops. Wrong way. Next try:

Starting count down:
9
8
7
6
5
4
3
2
1
0

Ooops. Need to start at 10. Next try:

Starting count down:
10
9
8
7
6
5
4
3
2
1
Blast off!

public class counting
{
   public static void main (String args [])
   {
   new counting ();
   }

   public counting ()
   {
   System.out.println ("Starting count down: ");
   int i = 0;
   while (i < 10)
   {
   i++;
   System.out.println (i + "");
   }
   
   System.out.println("\nOoops. Wrong way. Next try: ");
   System.out.println ("\nStarting count down: ");
   i = 10;
   while (i >0)
   {
   i--;
   System.out.println (i + "");
   }
   
   System.out.println("\nOoops. Need to start at 10. Next try: ");
   System.out.println ("\nStarting count down: ");
   i = 10;
   while (i >0)
   { 
   System.out.println (i + "");
   i--;
   }
   System.out.println("Blast off!");

}
}