generateRandomNumber()

Step 1: Import the Random Library

Firstly, we have to import java's built-in java.util.Random library, which allows us to generate random numbers.

import java.util.Random;

Step 2: Instantiate the Random Class

Next, we create an instance of the Random class.

Random rand = new Random();

Step 3: Generate Random Integer

Then, we can generate a random number using the nextInt() method provided by the Random class. In this step, I will generate a random number between 0 and 100.

int randomNum = rand.nextInt(100);

Step 4: Output the Random Number

Now, we just have to print out the generated number. We will do this using System.out.println as shown below:

System.out.println(randomNum);

Step 5: Wrap All Steps Inside a Function

Lastly, we need to wrap the previous steps inside a function for reusability. Let's create a function named generateRandomNumber:

public static int generateRandomNumber() {
    Random rand = new Random();
    int randomNum = rand.nextInt(100);
    System.out.println(randomNum);
    return randomNum;
}

And that's it! we have successfully created a function in Java that generates and prints out a random number between 0 and 100. Bear in mind that this function can be customized to generate numbers between any two values, not just 0 and 100, by modifying the argument passed to the nextInt() method.