CSIS 110 - Lecture 23
Announcements:
Read section 5.5, 5.6, 5.8, and 5.9 (last time: 5.1 to 5.4)
Last Time: Random Numbers
Java includes a class for generating random numbers. What is it called?
What package is it contained in? (That is, where do you need to tell Java to look for the
Random class in an import statement?)
How do you create an instance of a Random?
How do you generate a random number?
- create an instance of class Random
- call a method on that object to get a number
-
Discuss ways that students used random numbers to select DNA characters.
The class Random has an overloaded constructor:
public Random()
public Random( long seed )
Both create a random number generator. The second version takes a seed value as a
parameter. This "primes" the generator. Two random number generators created using the
same seed value will generate the same sequence of 'random' numbers.
The nextInt method returns a random number. This method is also overloaded:
public int nextInt() โ return a random int in the range -2,147,484,648 to
2,147,484,647.
public int nextInt( int max ) โ return a random int in the range 0 to
max-1.
So, how would we use a Random number generator to simulate rolling a single die? How
about two dice?
