Answer Key for Practice Quiz 3

1. Write an expression that evaluates to true if and only if the integers i and j are greater than 10.

       i > 10 && j > 10
   

2. Write an expression that evaluates to true if and only if i is positive or less than -10.

       i > 0 || i < -10
   

3. Given an integer variable, hour, that has a value in the range of 0 - 23, declare a new String variable called suffix and initialize it to "AM" or "PM", depending on the value of hour. (0 - 11 should be "AM"; 12 - 23 should be "PM".)

       if ( hour < 12 )
       {
           suffix = "AM";
       }
       else
       {
           suffix = "PM";
       }
   

4. Write a for loop that prints "Hooray!" 10 times, each time on a separate line.

       for ( int i = 0; i < 10; i++ )
       {
           System.out.println("Hooray!");
       }
   

5. Declare a variable of type WordReader and initialize it to a new WordReader object. The WordReader constructor takes one parameter, a file name of type String. You can pass whatever string you like to the constructor as the filename.

       WordReader reader = new WordReader("SherlockHolmes.txt");
   

6. Using the WordReader variable you declared and initialized above, use the nextLine() method to read in a line and print it. The nextLine() method does not take any parameters; it returns a String.

       System.out.println(reader.nextLine());
   
       // OR, String theLine = reader.nextLine();
       //     System.out.println(theLine);
   

Answer Key for Practice Quiz on Constructing and Looping through an ArrayList

1. Declare a variable named words that is an ArrayList of String values, and initialize it to be an empty list.

       ArrayList<String> words = new ArrayList<String>();
   

2. Add three strings to the ArrayList you created above: “Sherlock”, “Holmes”, and "Watson".

       words.add("Sherlock");
       words.add("Holmes");
       words.add("Watson");
   

3. Write a for loop that prints the length of each string in the ArrayList you created above.

       for ( String oneWord : words )
       {
           int len = oneWord.length();
           System.out.println(len);    // OR, System.out.println(oneWord.length());
       }