Pre-Lab Assignment: Lab #2

1. What is the difference between a variable and a constant?

   
   
   

2. Explain what each of the lines below does. Be sure to indicate how each is different from the others.
   1. int x;

      
      

   2. int x = 3;

      
      

   3. x = 3;

   
   

3. The following program reads three integers and prints the average. Fill in the blanks so that it will work correctly.

   
   // **********************************************
   // FILE: Average.java
   // Author: Adrienne Bloss
   //
   // Purpose: Read three integers from the user and print their average
   // **********************************************
   
   import cs1.Keyboard;
   public class Average
   {
     public static void main(String[] args)
     {
       int val1, val2, val3;
       double average;
   
       // get three values from user
       System.out.println("Please enter three integers and " +
                          "I will compute their average");
   
       ____________________________________
   
       ____________________________________
   
       ____________________________________
   
       //compute the average
   
       ____________________________________
   
       //print the average
   
       ____________________________________
   
     }
   
   }
   

   
   
   
   
4. Given the declarations below, find the result of each expression.

   int a = 3, b = 10, c = 7;
   double w = 12.9, y = 3.2;
   
   a + b * c
   
   a - b - c
   
   a / b
   
   b / a
   
   a - b / c
   
   w / y
   
   y / w
   
   a + w / b
   
   a % b / y
   
   b % a
   
   w %  y