Computer Programming
The Math.random method generates a random number x, such that
0 <=x<1
Possible output? For (int k=1;k<=10; k++) { double var1=Math.random() * 100; int var2 = (int) var1 +10 ; System.out.print(var2 + ". ")
10 numbers, lowest variable 10, highest no greater than 100
how many objects are being shown? (revert to the study guide)
13 (13 bugs placed on the grid)
Approximately how many different graphics colors can Java produce?
16,000,000
how many classes are being shown? (revert to study guide)
5 (5different types of bugs)
Output? import Java.util.Random; public static void main (String args []) { Random rand= new Random(); rand.setSeed(100); System.out.println(rand.nextDouble()); System.out.println(rand.nextDouble()); System.out.println(rand.nextDouble()); System.out.println(rand.nextDouble()); System.out.println(rand.nextDouble());
5 double numbers greater or equal to zero and less than 1
Math.sqrt(81); The method sqrt in the Math class is
A class method
Assume rand is an object of the Random Class. What is the output of this statement? System.out.println(rand.nextInt(1000));
A random number between 0 and 999
Assume rand is an object of the Random Class. What is the output of this statement? System.out.println(rand.nextInt(1001));
A random number between 0 to 1000
Assume rand is an object of the Random Class. What is the output of this statement? int x = rand.nextInt(1000)+1 System.out.println(x);
A random number from 1 to 1000
What is the output of the following statement? System.out.println( (int) (100*Math.random());
An integer in the [0...99] range
Bank Tom =new Bank (); What is Tom?
An object
Bank Tom =new Bank (); What is bank?
An object method
In the statement Bank tom = new Bank(5000.0); What is the class?
Bank
nextInt and nextDouble are methods of what classes?
Both Random and Scanner
Integer.MAX_VALUE and Integer.MIN_VALUE
Can be accessed like Math.PI,are constant values, are members of the Integer class
2.Integer.MAX_Value and Integer.MIN_VALUE
Constant fields or attributes
A class is a
Data type
DrawPolygon and fillPolygon are both methods of the _ class
Graphics
Which class makes it possible to draw a six sided polygon?
Polygon
nextInt and nextDouble are both methods of which classes?
Random and Scanner
Which if these statements will cause a different set of random numbers to be generated every time the program is executed?
Random rand = new Random ();
The new Java keyword must be used with
The construction of each object
Using the scanner class with numbers and strings can have unexpected results. This unexpected result can be cured by
Using a dummy String variables
An object is a type of
Variable
Java can combine 3 primary colors to create virtually any color. Which of the following is NOT one of those colors?
Yellow (rgb)
What is int?
a data type
Objects without identifiers are called ___ objects
anonymous
Which of the following statement generates a random character in the [A...Z] range?
char number = (char) (rand.nextInt(26)+65);
An example of a named object
g.setColor(myRed);
An example of an anonymous object?
g.setColor(newColor(100,100,100));
Which of the following statement generates a random number in the [0..100] range?
int number = rand.nextInt(101);
Which of the following statement generates a random number in the [-41..101] range?
int number = rand.nextInt(143)-41;
Which of the following statement generates a random number in the [200..600]range?
int number = rand.nextInt(401)+200;
Assume rand is an Object of the random class which of the following statements will cause Xt to have a random value in the same range as this statement Int x = rand.nextInt(1001) +500;
int x = (int) (Math.random() * 1001 + 500);
Assume rand has is an object of the Random class Which of the following statements will cause x to have a random value between 100 and 500
int x = rand.nextInt(401)+100;
The Random class is found inside the ________ package
java.util
The random method of the math class behaves Just like the_____ method of the _____ class.
nextDouble, Random
Which of the following are methods of the Random Class
nextInt, nextDouble, setSeed
Which graphics method changes color?
setColor
Access to methods of the Bank class requires
the creation of one of more Bank objects
In the statement Bank tom = new Bank(5000.0); Which is the object?
tom
Integer and Double are
wrapper classes