1.2.2 Variables and Types

Which of the following is a proper way to declare and initialize an int variable in Java?

int myNumber = 10;

Consider the following code snippet.

public static void main(String args[]){
    final int z;
    z = 20;
    z = 30;
    System.out.println(z);
}

What value of z is actually printed?

This code gives an error.

What are the memory values associated with the variables x, y, and z after the code snippet below executes?

int x = 7;            
double y = 2.0;             
boolean z = false;

x = x + 3;             
z = true;

x holds the int value 10, y holds the double value 2.0 and z holds the boolean value true.

Which of the following variable names follows best practices for naming a variable?

5apples

someVariable

applesnum

numApples

numApples

What does the keyword final do?

It prevents variables from being altered.

What will be the output of the following code snippet:

public class Variables 
{
    public static void main(String[] args)
    {
        int totalBirds = 150;
        double averageTime = 45.7;
        String mostCommon = "Mallard Duck";

        System.out.println("Bird Watching Results");
        System.out.print("Total birds seen: ");
        System.out.println(totalBirds);

        System.out.print("Average time between sightings: ");
        System.out.println(averageTime);

        System.out.print("Most common bird seen was ");
        System.out.println(mostCommon);
    }
}

Bird Watching Results
Total birds seen: 150
Average time between sightings: 45.7
Most common bird seen was Mallard Duck