Java Basics – Class To Generate Random Output To Screen After Manipulation Of Input

Class To Generate Random Output To Screen After Manipulation Of Input

Integer Manipulation

Here’s an example Java class that demonstrates a method to take a random integer, multiply it by 3, and return the result. The main method calls this method, prints the result, and includes all necessary syntax and documentation of the prepared code.

import java.util.Random;
public class IntegerMultiplier {

    public static void main(String[] args) {
        int randomNumber = getRandomInteger();
        int result = multiplyByThree(randomNumber);
        
        System.out.println("Random Integer: " + randomNumber);
        System.out.println("Result after multiplying by 3: " + result);
    }

    // Method to generate a random integer between 1 and 10
    private static int getRandomInteger() {
        Random random = new Random();
        return random.nextInt(10) + 1; // Generates a number between 1 and 10
    }

    // Method to multiply an integer by 3
    private static int multiplyByThree(int number) {
        return number * 3;
    }
}

Explanation:

• getRandomInteger: Generates a random integer between 1 and 10 by using random.nextInt(10) + 1. Adding 1 ensures the random number is within 1 to 10 (inclusive).
• multiplyByThree: Takes an integer as input and returns the result of multiplying it by 3.
• main Method: Calls getRandomInteger, then calls multiplyByThree with the random integer, and prints both the original and multiplied results.
  

Sample Output:

Random Integer: 4
Result after multiplying by 3: 12

This code provides a clear example of generating a random integer, performing a multiplication, and displaying the results.

String Manipulation

Here’s an example Java class that demonstrates a method that takes a string, repeats it three times, and then returns the result. The main method will call this method, print the result to the screen, and include all the proper syntax and documentation of the prepared code.

import java.util.Random;

public class StringMultiplier {

    public static void main(String[] args) {
        String randomString = getRandomString();
        String result = multiplyStringByThree(randomString);
        
        System.out.println("Original String: " + randomString);
        System.out.println("Multiplied String: " + result);
    }

    // Method to generate a random string
    private static String getRandomString() {
        String[] possibleStrings = {"apple", "banana", "cherry", "date", "fig"};
        Random random = new Random();
        return possibleStrings[random.nextInt(possibleStrings.length)];
    }

    // Method to multiply a string by 3
    private static String multiplyStringByThree(String input) {
        return input.repeat(3);
    }
}

Explanation:

• getRandomString generates a random string from a predefined list of possible strings.
• multiplyStringByThree takes an input string and uses the String.repeat(int count) method to concatenate it three times.
• The main method gets a random string, multiplies it, and prints both the original and multiplied strings.
  

Sample Output:

Original String: banana
Multiplied String: bananabananabanana

This code provides a clear example of generating a random string, repeating the string 3 times, and displaying the results.

Java Library Method Used

The random.nextInt(int bound) method in Java is used to generate a random integer between 0 (inclusive) and the specified bound (exclusive).

Here’s how it works:

• Syntax: random.nextInt(bound)
• Parameter: The bound specifies the upper limit for the generated random number (exclusive).
• Return Value: It returns a random integer between 0 (inclusive) and bound (exclusive).
  

For example:

Random random = new Random();
int randomNumber = random.nextInt(5);
System.out.println(randomNumber);

In this example:

• random.nextInt(5) will generate a random integer between 0 and 4 (i.e., one of 0, 1, 2, 3, or 4).

This method is particularly useful when you need to pick a random index from an array or list, as in the code we used earlier.

Tutorial Tags