Math and Random
The value of result after executing the following statement.
int result = (int) Math.pow(3, 2);
What is 9?
This line of code will print the traditional Computer Science greeting of "Hello world!"
What is
System.out.println("Hello World!");
public class Book
{
private int numPages;
// Some code omitted from this class
public void setNumPages(int pages)
{
numPages = pages;
}
public int getNumPages()
{
return numPages;
}
}
The name of the instance variable given in the Book class.
What is numPages?
It is the result of the code segment below.
String[] weekdays = {"Mon", "Tue", "Wed", "Thurs", “Fri”};
System.out.println(weekdays.length);
System.out.println(weekdays[1]);
System.out.println(weekdays[5]);
What is an Array Index Out of Bounds Exception?
It is the value of variable val after the following code segment has executed.
int num1 = 7, num2 = 1, num3 = 5, x1 = 2, x2 = 8, val = 0;
if (x1 < x2)
{
if (num1 != num2)
val++;
else
val--;
}
else
val = x1 + x2;
What is 1?
The line of Java code that will correctly calculate the square root of 45 and store it in a double variable called num.
What is
double num = Math.sqrt(45);
The output of the following code segment.
boolean coldTemps = false;
int month = 4;
if (coldTemps && (month < 3))
System.out.println("Winter");
else if (month == 3 || month == 4)
System.out.println("Spring-ish");
else if (!coldTemps && month > 4)
System.out.println("Summer");
else
System.out.println("Fall");
What is Spring-ish?
public class Book
{
private int numPages;
// Some code omitted from this class
public void setNumPages(int pages)
{
numPages = pages;
}
public int getNumPages()
{
return numPages;
}
}
The name of the accessor method in the Book class.
What is getNumPages?
It is the line of code that will create an array (named letters) of 5 Strings and initialize them to the letters “A” - ”E” (in order) using an initializer list.
String [] letters = {"A", "B", "C", "D", "E"};
It is the location (x and y) of the shape drawn in the following line of code:
grph.drawRect(30, 40, 80, 100);
What is (30, 40)?
The range of possible values that could be assigned to num in the code segment below.
int num = (int) (Math.random() * 20 - 10);
The output of the following code segment?
int x = 0;
for (int index = 3; index < 12; index += 3)
{
x += index;
}
System.out.println("x is : " + x);
What is "x is 18"?
public class Book
{
private int numPages;
// Some code omitted from this class
public void setNumPages(int pages)
{
numPages = pages;
}
public int getNumPages()
{
return numPages;
}
}
The name of the mutator (modifier) method in the Book class.
What is setNumPages?
It is a code segment that will correctly declare and instantiate an array (named strArray) of 20 Strings. It does not need to assign any values to the specific Strings.
What is
String [] strArray = new String[20];
It is the name given to the following boolean expression where only the first condition is checked.
int x=10;
int y = 0;
if(x==y && y < 20)
What is a short circuit?
This Java statement will generate a random integer in the [ 5..15 ] range.
What is
int val = (int) (Math.random() * 11 + 5);
The output of the following code segment.
int index = 1, x = 0;
while (x <= 6)
{
index++;
x += index;
}
System.out.println(x);
What is 9?
public class Book
{
private int numPages;
// Some code omitted from this class
public void setNumPages(int pages)
{
numPages = pages;
}
public int getNumPages()
{
return numPages;
}
}
This line of code will declare and instantiate a Book object named b using a default constructor (no parameters).
What is
Book b = new Book();
It is the missing code below that will allow the loop to count how many array elements are multiples of 5.
for(int i = 0; i < vals.length; i++)
{
/* MISSING CODE */
count++;
}
What is
if(vals[i] % 5 == 0)
Assume that grph is a graphics object. This line of code will produce a circle with a diameter of 150 located at the pixel (100, 20)?
grph.drawOval(100,20,150,150);
This line of code will print the absolute value of a variable named var.
What is
System.out.println(Math.abs(var));
The result of the following code segment.
for (int i = 1; i < 20; i *= 2)
{
int count = count + 1;
}
System.out.print(“count is “ + count);
What is a syntax error?
public class Book
{
private int numPages;
// Some code omitted from this class
public void setNumPages(int pages)
{
numPages = pages;
}
public int getNumPages()
{
return numPages;
}
}
It's how you print out the number of pages in a Book object called b from a main method class. You may assume the object b has already been declared and instantiated correctly.
What is
System.out.println(b.getNumPages());
It is a for loop that will successfully increment every element in an array named vals.
What is
for(int i=0; i < vals.length; i++)
vals[i]++;
It is the line of code that would compare if the following two Strings named name1 and name2 are storing the same name.
What is
if(name1.equals(name2))