CS100 M
Review Questions for Prelim 3

Question 1

What is the output of the following program segment?

       int k, j=2, m=3;

       for (k=0; k<=m; k++)

            System.out.println("k= "+ k);

            j += 3*k;

            System.out.println("j= "+ j);

Question 2

Write a program segment that reads a non-negative integer n and outputs a triangle with n ASCII characters on each side. The n lines of the triangle alternately contains asterisks (*) and question marks (?). E.g., if the input is 5, the following pattern should be printed:

*

??

***

????

*****

Question 3

Experiment with classes Interval and Person developed in lecture: (1) write more "client code" to learn to call methods, (2) add more methods to Interval and/or Person.

Question 4

Fill in the blanks to complete classes Sphere and Calculation below. Class Calculation is the client of Sphere. Read through both incomplete classes before you start writing. It may be helpful to complete class Sphere before class Calculation. Pay attention to the comments.

  public class Calculation {

     public static void main(String[] args) {

        // create two Sphere objects



	   ________________ ball =   ________________________(4.0,"ball");



	   ________________ orange = ________________________(4.0,"orange");



	// compute volume of the ball



           ________________ ballVol = ________________________;



        // print a description of the orange



           ___________________________________________________;

     } //method main

  } //class Calculation



  public class Sphere {



     ____________ double radius;      // radius of sphere



     ____________ ____________ type;  // what the sphere is



     // Constructor: assign values to the two instance variables of the Sphere



     ____________ ____________(____________ r, ____________ t) {

      ____________________________________________________________________

     |                                                                    |

     |                                                                    |

     |                                                                    |

     |____________________________________________________________________|

     } //constructor



     // instance method getVolume for calculating volume of the Sphere

      ____________________________________________________________________

     |                                                                    |

     |                                                                    |

     |                                                                    |

     |                                                                    |

     |____________________________________________________________________|



     // define a toString method for showing the type and radius of the Sphere

      ____________________________________________________________________

     |                                                                    |

     |                                                                    |

     |                                                                    |

     |                                                                    |

     |____________________________________________________________________|

  } //class Sphere