// Illustrate while, for, and do loops.
// Also illustrate the switch statement.

public class Structured 
{
    public static void main(String[] args)
    {
        int x;
        String word;

        // Using a while loop
        x = 1;
        while(x < 100)
        {
            System.out.print(x + " ");
            x *= 2;
        }
        System.out.println();

        // Using a for loop
        for(x = 1; x < 100; x *= 2)
            System.out.print(x + " ");
        System.out.println();

        // Using a do loop.  A do loop is guarenteed
        // to execute at least once.
        x = 1;
        do {
            System.out.print(x + " ");
            x *= 2;
        } 
        while(x < 100);
        System.out.println();
        System.out.println();
               
        // Using a switch statement.  A switch
        // statement chooses from among a list
        // of constants.
        x = 2;
        switch(x)
        {
            case 1:  word = "one";   break;
            case 2:  word = "two";   break;
            case 3:  word = "three"; break;
            default: word = "many";
        }
        System.out.println("word == \"" + word + "\"");
        
        // Exercise.  Convert the preceding
        // switch statement to an if..else 
        // statement.
    }
}

// Output:
1 2 4 8 16 32 64 
1 2 4 8 16 32 64 
1 2 4 8 16 32 64 

word == "two"