AP Computer Science Exam Question

Explain the purpose and usage of the Random class in Java. Provide an example code that demonstrates the generation of random numbers using this class.

Answer

The Random class in Java is used to generate random numbers. It is commonly used in various applications where randomization is required, such as game development, statistical simulations, and cryptography. The Random class provides methods to generate random integers, floating-point numbers, and boolean values.

The key steps to use the Random class are as follows:

1. Import the java.util.Random class:

   import java.util.Random;
   

2. Create an instance of the Random class:

   Random random = new Random();
   

3. Use the appropriate methods to generate the desired random numbers. Some commonly used methods are:

   • nextInt(int n) - generates a random integer between 0 (inclusive) and n (exclusive).
   • nextDouble() - generates a random floating-point number between 0.0 (inclusive) and 1.0 (exclusive).
   • nextBoolean() - generates a random boolean value (true or false).

Here is an example code that demonstrates the generation of random numbers using the Random class:

import java.util.Random;

public class RandomGeneratorExample {
    public static void main(String[] args) {
        Random random = new Random();

        // Generate a random integer between 1 and 10
        int randomNumber = random.nextInt(10) + 1;
        System.out.println("Random Integer: " + randomNumber);

        // Generate a random floating-point number between 0.0 and 1.0
        double randomDouble = random.nextDouble();
        System.out.println("Random Double: " + randomDouble);

        // Generate a random boolean value
        boolean randomBoolean = random.nextBoolean();
        System.out.println("Random Boolean: " + randomBoolean);
    }
}

In this example, the nextInt(10) + 1 generates a random integer between 1 and 10 (inclusive). The nextDouble() generates a random floating-point number between 0.0 and 1.0. The nextBoolean() generates a random boolean value.

Please note that the random numbers generated by the Random class are pseudorandom, which means they are determined by a mathematical algorithm and can be reproduced if the same seed is used.