PreLab 7: Selection and Type boolean

  1. As activity directory at Lake Lazydays Resort, it is your job to suggest appropriate activities to guests based on the weather. You recommend that when the temperature is greater than 95 or less than 20 people should visit the resort shops. Otherwise you recommend the following activities:
      temp >= 80:         swimming
      60 <= temp < 80:    tennis
      40 <= temp < 60:    golf   
      20 <= temp < 40:    skiing 
    Fill in the blanks in the code below as directed in the comments. The if should be a cascading if with conditions that are no more complicated than necessary.
      int temp;
      System.out.println("What's the temperature today?");
      temp = scan.nextInt();
      // Declare a boolean variable extremeTemp and assign it an
      // expression that is true when the temperature is greater than 95 or
      // less than 20
      // Complete the cascading if (avoid unnecessary comparisons)
      if (extremeTemp)
        System.out.println ("Visit our shops!");
      else if (temp >= 80)
        System.out.println("How about a dip in the pool?");
        System.out.println("Go grab a racquet!");
        System.out.println("It's a perfect day for golf.");
        System.out.println("Let's hit the slopes!");

  2. Rewrite each condition below in valid Java syntax (give a boolean expression):
    1. x > y > z



    2. neither x nor y is equal to 0



    3. both x and y are equal to 0



    4. x is greater than y but less than z


  3. Use truth tables to determine whether each pair of expressions is equivalent. Show steps!
    1. NOT q OR p
      p OR NOT(q OR p)

    2. (p AND r) OR (q AND NOT r)
      (p AND q AND NOT r)

  4. Use the laws of logic to write a Java expression equivalent to the following without using the not (!) operator:
         !(age >= 65 && income < 20000)
  5. Use the laws of logic to simplify the following statement as much as possible. State which law you are using at each step.
          p OR NOT (p OR (p OR q))