Overview Lesson #2

Below is a list of all the lessons this overview lesson will cover.

  1. The Scanner Class
  2. Arrays
  3. Foreach Loops
  4. The Math Class
  5. Errors/Exceptions
  6. Methods
  7. Advanced Methods

Lesson Quiz

Each question in this quiz corresponds to that lesson, so if you miss a specific problem, go back to that problem’s lesson to review.

1. What is the correct syntax of creating a variable s of type Scanner, reading input from the console?

a. new Scanner s = Scanner(new File(“user.txt”));
b. Scanner s = new Scanner(System.in);
c. new Scanner(new File(“user.txt”)) = Scanner s;
d. Scanner s = new Scanner(new File(“user.txt”));

2. Which signature line is for a method with three int parameters( a, b, c ), returns a String, has a name “method1”, and should not be accessed outside of the class.

a. public (int a, int b, int c) method1 String {...}
b. private method1 String (int a, int b, int c) {...}
c. private String (int a, int b, int c) method1 {...}
d. private String method1(int a, int b, int c) {...}

3. Which is the proper way of declaring a three dimensional int array of dimensions 5x5x5?

a. int[[[]]] arr = new int[ 5 [ 5 [5] ] ];
b. int[][][] arr = new int[5][5][5];
c. int{} arr = new int{ { {5} } };
d. int[] arr = new int[5]int[5]int[5];

4. What is the syntax of a foreach loop which traverses a one dimensional String array, “ar”, of length 7?

a. for (ar : String s) {...}
b. for (String[7] ar : String s) {...}
c. for (String s : ar) {...}
d. for (String s : String[7] ar) {...}

5. What is the result of the below statement?

    Math.abs(-1 * Math.sqrt(3 * Math.pow(3, 3)))
a. 9
b. 9.0
c. 3
d. -81.0

6. What will occur from the following code?

    int a = 1;
    while (a != 0) {
        a *= 4;
    }
a. An infinite loop will occur.
b. ArrayIndexOutOfBoundsException will be thrown.
c. ClassCastException will be thrown.
d. NullPointerException will be thrown.

7. Will an exception be thrown from the following method declarations?

    public void method1() {...}
    public void method1(int a) {...}
a. Yes
b. No

Written by James Richardson

Notice any mistakes? Please email us at [email protected] so that we can fix any inaccuracies.