Introduction to Java Programming

1 Suppose a Scanner object is created as follows:

Scanner input = new Scanner(System.in);

What method do you use to read an int value?

A. input.nextInt();

B. input.nextInteger();

C. input.int();

D. input.integer();

2 The following code fragment reads in two numbers:

Scanner input = new Scanner(System.in);
int i = input.nextInt();
double d = input.nextDouble();

What are the correct ways to enter these two numbers?

A. Enter an integer, a space, a double value, and then the Enter key.

B. Enter an integer, two spaces, a double value, and then the Enter key.

C. Enter an integer, an Enter key, a double value, and then the Enter key.

D. Enter a numeric value with a decimal point, a space, an integer, and then the Enter key.

3 If you enter 1 2 3, when you run this program, what will be the output?

import java.util.Scanner;

public class Test1 {
  public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.print("Enter three numbers: ");
    double number1 = input.nextDouble();
    double number2 = input.nextDouble();
    double number3 = input.nextDouble();

    // Compute average
    double average = (number1 + number2 + number3) / 3;

    // Display result
    System.out.println(average);
  }
}

A. 1.0

B. 2.0

C. 3.0

D. 4.0

4 What is the exact output of the following code?

  double area = 3.5;
  System.out.print("area");
  System.out.print(area);

A. 3.53.5

B. 3.5 3.5

C. area3.5

D. area 3.5

7 Which of the following are correct names for variables according to Java naming conventions?

8 Which of the following are correct ways to declare variables?

A. int length; int width;

B. int length, width;

C. int length; width;

D. int length, int width;

Introduction to Java Programming, Eighth Edition, Y. Daniel Liang

Chapter 2 Elementary Programming