Java: Loop Quiz

OPEN BOOK. g is a Graphics object.

1. (2 points) Draw the output from the following code:

   for (int i=10; i<=30; i += 10) {
       g.drawRect(i, i, i, i);
   }
   

2. (3 points) Draw the output from the following code:

   int y = 20;
   int n = 3;
   while (n > 1) {
       g.drawString("n = " + n, 20, y);
       y += 20;
       if (n%2 == 0) {
           n = n / 2;
       }else{
           n = 3*n + 1;
       }
   }
   

3. (4 points) Draw the output from the following code:

   boolean fill = true;
   for (int col=1; col<=5; col++) {
       fill = (col%2 == 1);
       for (int row=1; row<=4; row++) {
           if (fill) {
               g.fillOval(col*10, row*10, 5, 5);
           }else{
               g.drawOval(col*10, row*10, 5, 5);
           }
           fill = !fill;
       }
   }
   

4. (4 points) Assume the following value for s before each of the independent questions.

       s = "buenas";
       

   What is the value in s after executing the following code?

   1. __________________ s = s.substring(0,1).toUpperCase() + s.substring(1, s.length()-1);
   2. __________________ s = "" + Character.toUpperCase(s.charAt(3));
   3. __________________ s = s.substring(1).substring(1);
   4. __________________ s.toUpperCase(); // Warning: this is a trick question.