import java.util.Scanner;

public class WhileLoop {
 public static void main(String[] args) {
   // LOOP: tells your machine to print "Hello World" 5 times
   // begin loop:
   int count = 1;
   while (count <= 5) {
     System.out.println("Hello World (" + count + ")");
     count++;
   }
   // convert the above while to a for loop
   // for (initialization; condition; update)
   System.out.println("for loop is executing: ");
   int i;
   for (i=0; i<5; i++) {
      System.out.println("Hello World (" + i + ")");
   }
   System.out.println("when I fall out of for loop is is: " + i);
     
     
     
   // end loop
   // this loop does the same thing just it counts down
   int limit = 5;
   while (limit > 0) {
     System.out.println("Hello World (" + limit + ")");
     limit--;
   }
   Scanner sc = new Scanner(System.in);
   System.out.println("How many times do you want to loop? ");
   limit = sc.nextInt();
   count = 1; // use count to count up to the limit
   while (count <= limit) {
     System.out.println("count: " + count++);
   }
   
   // algorithm for summing
   // sum up all the numbers that I read in
   /*
   System.out.println("Enter next number: ");
   int num, sum=0;
   while (sc.hasNext()) {
     num=sc.nextInt();
     sum+=num;
     System.out.println("Enter next number: ");
   }
   System.out.println("sum is: " + sum);  
   sc.close();
   */
   
   // do while
   // executes once before condition is tested
   Scanner keyboard = new Scanner(System.in);
   int choice;
   do {
     System.out.println("Phone Plan Menu:\n1. Option 1\n4. Exit");
     choice = keyboard.nextInt();
   }while(choice!=4);
   
   // input validation
   // while input is not valid
   //   have the user enter a different input
   // data value has to be between 1 and 100
   System.out.println("Enter next piece of data (1-100): ");
   int data = keyboard.nextInt();  
   while (data < 1 || data > 100) {
      System.out.println("Data is not valid, try again (1-100): ");
      data = keyboard.nextInt();
   }
     
     
  // Here's an example of a while loop that does not count
   /*
   while (guess != myNumber) {
     // enter another guess
   }
   boolean youWon=false;
   while (!youWon) {
     // enter another guess
     if (guess==myNumber)
       youWon=true;
   }// end while loop
   **/
   // show Math.random for Assignment 3
   double number = Math.random() * 100; // moves decimal pt over twice
   int myNumber = (int)number; // casting to an int
   // write a while loop that will ask the user to enter a character
   // and will terminate when the user enters 'n' for no
   // count number of iterations
   /**
   count = 0;
   char myChar = 'y';
   while (myChar != 'n')  {
      System.out.println("Enter a char# " + count  +", n to finish:");
      myChar = sc.next().charAt(0);
      count++;
   }
   System.out.println("count is: " + count);
   **/
 }
}